--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CSP2/CSP2_env/env-d9b9114564458d9d-741b3de822f2aaca6c6caa4325c4afce/include/unicode/ucal.h	Tue Mar 18 17:55:14 2025 -0400
@@ -0,0 +1,1623 @@
+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+ *******************************************************************************
+ * Copyright (C) 1996-2015, International Business Machines Corporation and
+ * others. All Rights Reserved.
+ *******************************************************************************
+ */
+
+#ifndef UCAL_H
+#define UCAL_H
+
+#include "unicode/utypes.h"
+#include "unicode/uenum.h"
+#include "unicode/uloc.h"
+#include "unicode/localpointer.h"
+
+#if !UCONFIG_NO_FORMATTING
+
+/**
+ * \file
+ * \brief C API: Calendar
+ *
+ * <h2>Calendar C API</h2>
+ *
+ * UCalendar C API is used  for converting between a <code>UDate</code> object
+ * and a set of integer fields such as <code>UCAL_YEAR</code>, <code>UCAL_MONTH</code>,
+ * <code>UCAL_DAY</code>, <code>UCAL_HOUR</code>, and so on.
+ * (A <code>UDate</code> object represents a specific instant in
+ * time with millisecond precision. See UDate
+ * for information about the <code>UDate</code> .)
+ *
+ * <p>
+ * Types of <code>UCalendar</code> interpret a <code>UDate</code>
+ * according to the rules of a specific calendar system. The U_STABLE
+ * provides the enum UCalendarType with UCAL_TRADITIONAL and
+ * UCAL_GREGORIAN.
+ * <p>
+ * Like other locale-sensitive C API, calendar API  provides a
+ * function, <code>ucal_open()</code>, which returns a pointer to
+ * <code>UCalendar</code> whose time fields have been initialized
+ * with the current date and time. We need to specify the type of
+ * calendar to be opened and the  timezoneId.
+ * \htmlonly<blockquote>\endhtmlonly
+ * <pre>
+ * \code
+ * UCalendar *caldef;
+ * UChar *tzId;
+ * UErrorCode status;
+ * tzId=(UChar*)malloc(sizeof(UChar) * (strlen("PST") +1) );
+ * u_uastrcpy(tzId, "PST");
+ * caldef=ucal_open(tzID, u_strlen(tzID), NULL, UCAL_TRADITIONAL, &status);
+ * \endcode
+ * </pre>
+ * \htmlonly</blockquote>\endhtmlonly
+ *
+ * <p>
+ * A <code>UCalendar</code> object can produce all the time field values
+ * needed to implement the date-time formatting for a particular language
+ * and calendar style (for example, Japanese-Gregorian, Japanese-Traditional).
+ *
+ * <p>
+ * When computing a <code>UDate</code> from time fields, two special circumstances
+ * may arise: there may be insufficient information to compute the
+ * <code>UDate</code> (such as only year and month but no day in the month),
+ * or there may be inconsistent information (such as "Tuesday, July 15, 1996"
+ * -- July 15, 1996 is actually a Monday).
+ *
+ * <p>
+ * <strong>Insufficient information.</strong> The calendar will use default
+ * information to specify the missing fields. This may vary by calendar; for
+ * the Gregorian calendar, the default for a field is the same as that of the
+ * start of the epoch: i.e., UCAL_YEAR = 1970, UCAL_MONTH = JANUARY, UCAL_DATE = 1, etc.
+ *
+ * <p>
+ * <strong>Inconsistent information.</strong> If fields conflict, the calendar
+ * will give preference to fields set more recently. For example, when
+ * determining the day, the calendar will look for one of the following
+ * combinations of fields.  The most recent combination, as determined by the
+ * most recently set single field, will be used.
+ *
+ * \htmlonly<blockquote>\endhtmlonly
+ * <pre>
+ * \code
+ * UCAL_MONTH + UCAL_DAY_OF_MONTH
+ * UCAL_MONTH + UCAL_WEEK_OF_MONTH + UCAL_DAY_OF_WEEK
+ * UCAL_MONTH + UCAL_DAY_OF_WEEK_IN_MONTH + UCAL_DAY_OF_WEEK
+ * UCAL_DAY_OF_YEAR
+ * UCAL_DAY_OF_WEEK + UCAL_WEEK_OF_YEAR
+ * \endcode
+ * </pre>
+ * \htmlonly</blockquote>\endhtmlonly
+ *
+ * For the time of day:
+ *
+ * \htmlonly<blockquote>\endhtmlonly
+ * <pre>
+ * \code
+ * UCAL_HOUR_OF_DAY
+ * UCAL_AM_PM + UCAL_HOUR
+ * \endcode
+ * </pre>
+ * \htmlonly</blockquote>\endhtmlonly
+ *
+ * <p>
+ * <strong>Note:</strong> for some non-Gregorian calendars, different
+ * fields may be necessary for complete disambiguation. For example, a full
+ * specification of the historical Arabic astronomical calendar requires year,
+ * month, day-of-month <em>and</em> day-of-week in some cases.
+ *
+ * <p>
+ * <strong>Note:</strong> There are certain possible ambiguities in
+ * interpretation of certain singular times, which are resolved in the
+ * following ways:
+ * <ol>
+ *     <li> 24:00:00 "belongs" to the following day. That is,
+ *          23:59 on Dec 31, 1969 &lt; 24:00 on Jan 1, 1970 &lt; 24:01:00 on Jan 1, 1970
+ *
+ *     <li> Although historically not precise, midnight also belongs to "am",
+ *          and noon belongs to "pm", so on the same day,
+ *          12:00 am (midnight) &lt; 12:01 am, and 12:00 pm (noon) &lt; 12:01 pm
+ * </ol>
+ *
+ * <p>
+ * The date or time format strings are not part of the definition of a
+ * calendar, as those must be modifiable or overridable by the user at
+ * runtime. Use {@link icu::DateFormat}
+ * to format dates.
+ *
+ * <p>
+ * <code>Calendar</code> provides an API for field "rolling", where fields
+ * can be incremented or decremented, but wrap around. For example, rolling the
+ * month up in the date <code>December 12, <b>1996</b></code> results in
+ * <code>January 12, <b>1996</b></code>.
+ *
+ * <p>
+ * <code>Calendar</code> also provides a date arithmetic function for
+ * adding the specified (signed) amount of time to a particular time field.
+ * For example, subtracting 5 days from the date <code>September 12, 1996</code>
+ * results in <code>September 7, 1996</code>.
+ *
+ * <p>
+ * The Japanese calendar uses a combination of era name and year number.
+ * When an emperor of Japan abdicates and a new emperor ascends the throne,
+ * a new era is declared and year number is reset to 1. Even if the date of
+ * abdication is scheduled ahead of time, the new era name might not be
+ * announced until just before the date. In such case, ICU4C may include
+ * a start date of future era without actual era name, but not enabled
+ * by default. ICU4C users who want to test the behavior of the future era
+ * can enable the tentative era by:
+ * <ul>
+ * <li>Environment variable <code>ICU_ENABLE_TENTATIVE_ERA=true</code>.</li>
+ * </ul>
+ *
+ * @stable ICU 2.0
+ */
+
+/**
+ * The time zone ID reserved for unknown time zone.
+ * It behaves like the GMT/UTC time zone but has the special ID "Etc/Unknown".
+ * @stable ICU 4.8
+ */
+#define UCAL_UNKNOWN_ZONE_ID "Etc/Unknown"
+
+/** A calendar.
+ *  For usage in C programs.
+ * @stable ICU 2.0
+ */
+typedef void* UCalendar;
+
+/** Possible types of UCalendars 
+ * @stable ICU 2.0
+ */
+enum UCalendarType {
+  /**
+   * Despite the name, UCAL_TRADITIONAL designates the locale's default calendar,
+   * which may be the Gregorian calendar or some other calendar.
+   * @stable ICU 2.0
+   */
+  UCAL_TRADITIONAL,
+  /**
+   * A better name for UCAL_TRADITIONAL.
+   * @stable ICU 4.2
+   */
+  UCAL_DEFAULT = UCAL_TRADITIONAL,
+  /**
+   * Unambiguously designates the Gregorian calendar for the locale.
+   * @stable ICU 2.0
+   */
+  UCAL_GREGORIAN
+};
+
+/** @stable ICU 2.0 */
+typedef enum UCalendarType UCalendarType;
+
+/** Possible fields in a UCalendar 
+ * @stable ICU 2.0
+ */
+enum UCalendarDateFields {
+  /** 
+   * Field number indicating the era, e.g., AD or BC in the Gregorian (Julian) calendar. 
+   * This is a calendar-specific value.
+   * @stable ICU 2.6 
+   */
+  UCAL_ERA,
+
+  /**
+   * Field number indicating the year. This is a calendar-specific value.
+   * @stable ICU 2.6 
+   */
+  UCAL_YEAR,
+
+  /**
+   * Field number indicating the month. This is a calendar-specific value. 
+   * The first month of the year is
+   * <code>JANUARY</code>; the last depends on the number of months in a year.
+   * @see #UCAL_JANUARY
+   * @see #UCAL_FEBRUARY
+   * @see #UCAL_MARCH
+   * @see #UCAL_APRIL
+   * @see #UCAL_MAY
+   * @see #UCAL_JUNE
+   * @see #UCAL_JULY
+   * @see #UCAL_AUGUST
+   * @see #UCAL_SEPTEMBER
+   * @see #UCAL_OCTOBER
+   * @see #UCAL_NOVEMBER
+   * @see #UCAL_DECEMBER
+   * @see #UCAL_UNDECIMBER
+   * @stable ICU 2.6 
+   */
+  UCAL_MONTH,
+
+  /**
+   * Field number indicating the
+   * week number within the current year.  The first week of the year, as
+   * defined by <code>UCAL_FIRST_DAY_OF_WEEK</code> and <code>UCAL_MINIMAL_DAYS_IN_FIRST_WEEK</code>
+   * attributes, has value 1.  Subclasses define
+   * the value of <code>UCAL_WEEK_OF_YEAR</code> for days before the first week of
+   * the year.
+   * @see ucal_getAttribute
+   * @see ucal_setAttribute
+   * @stable ICU 2.6 
+   */
+  UCAL_WEEK_OF_YEAR,
+
+ /**
+   * Field number indicating the
+   * week number within the current month.  The first week of the month, as
+   * defined by <code>UCAL_FIRST_DAY_OF_WEEK</code> and <code>UCAL_MINIMAL_DAYS_IN_FIRST_WEEK</code>
+   * attributes, has value 1.  Subclasses define
+   * the value of <code>WEEK_OF_MONTH</code> for days before the first week of
+   * the month.
+   * @see ucal_getAttribute
+   * @see ucal_setAttribute
+   * @see #UCAL_FIRST_DAY_OF_WEEK
+   * @see #UCAL_MINIMAL_DAYS_IN_FIRST_WEEK
+   * @stable ICU 2.6 
+   */
+  UCAL_WEEK_OF_MONTH,
+
+ /**
+   * Field number indicating the
+   * day of the month. This is a synonym for <code>DAY_OF_MONTH</code>.
+   * The first day of the month has value 1.
+   * @see #UCAL_DAY_OF_MONTH
+   * @stable ICU 2.6 
+   */
+  UCAL_DATE,
+
+ /**
+   * Field number indicating the day
+   * number within the current year.  The first day of the year has value 1.
+   * @stable ICU 2.6 
+   */
+  UCAL_DAY_OF_YEAR,
+
+ /**
+   * Field number indicating the day
+   * of the week.  This field takes values <code>SUNDAY</code>,
+   * <code>MONDAY</code>, <code>TUESDAY</code>, <code>WEDNESDAY</code>,
+   * <code>THURSDAY</code>, <code>FRIDAY</code>, and <code>SATURDAY</code>.
+   * @see #UCAL_SUNDAY
+   * @see #UCAL_MONDAY
+   * @see #UCAL_TUESDAY
+   * @see #UCAL_WEDNESDAY
+   * @see #UCAL_THURSDAY
+   * @see #UCAL_FRIDAY
+   * @see #UCAL_SATURDAY
+   * @stable ICU 2.6 
+   */
+  UCAL_DAY_OF_WEEK,
+
+ /**
+   * Field number indicating the
+   * ordinal number of the day of the week within the current month. Together
+   * with the <code>DAY_OF_WEEK</code> field, this uniquely specifies a day
+   * within a month.  Unlike <code>WEEK_OF_MONTH</code> and
+   * <code>WEEK_OF_YEAR</code>, this field's value does <em>not</em> depend on
+   * <code>getFirstDayOfWeek()</code> or
+   * <code>getMinimalDaysInFirstWeek()</code>.  <code>DAY_OF_MONTH 1</code>
+   * through <code>7</code> always correspond to <code>DAY_OF_WEEK_IN_MONTH
+   * 1</code>; <code>8</code> through <code>15</code> correspond to
+   * <code>DAY_OF_WEEK_IN_MONTH 2</code>, and so on.
+   * <code>DAY_OF_WEEK_IN_MONTH 0</code> indicates the week before
+   * <code>DAY_OF_WEEK_IN_MONTH 1</code>.  Negative values count back from the
+   * end of the month, so the last Sunday of a month is specified as
+   * <code>DAY_OF_WEEK = SUNDAY, DAY_OF_WEEK_IN_MONTH = -1</code>.  Because
+   * negative values count backward they will usually be aligned differently
+   * within the month than positive values.  For example, if a month has 31
+   * days, <code>DAY_OF_WEEK_IN_MONTH -1</code> will overlap
+   * <code>DAY_OF_WEEK_IN_MONTH 5</code> and the end of <code>4</code>.
+   * @see #UCAL_DAY_OF_WEEK
+   * @see #UCAL_WEEK_OF_MONTH
+   * @stable ICU 2.6 
+   */
+  UCAL_DAY_OF_WEEK_IN_MONTH,
+
+ /**
+   * Field number indicating
+   * whether the <code>HOUR</code> is before or after noon.
+   * E.g., at 10:04:15.250 PM the <code>AM_PM</code> is <code>PM</code>.
+   * @see #UCAL_AM
+   * @see #UCAL_PM
+   * @see #UCAL_HOUR
+   * @stable ICU 2.6 
+   */
+  UCAL_AM_PM,
+
+ /**
+   * Field number indicating the
+   * hour of the morning or afternoon. <code>HOUR</code> is used for the 12-hour
+   * clock.
+   * E.g., at 10:04:15.250 PM the <code>HOUR</code> is 10.
+   * @see #UCAL_AM_PM
+   * @see #UCAL_HOUR_OF_DAY
+   * @stable ICU 2.6 
+   */
+  UCAL_HOUR,
+
+ /**
+   * Field number indicating the
+   * hour of the day. <code>HOUR_OF_DAY</code> is used for the 24-hour clock.
+   * E.g., at 10:04:15.250 PM the <code>HOUR_OF_DAY</code> is 22.
+   * @see #UCAL_HOUR
+   * @stable ICU 2.6 
+   */
+  UCAL_HOUR_OF_DAY,
+
+ /**
+   * Field number indicating the
+   * minute within the hour.
+   * E.g., at 10:04:15.250 PM the <code>UCAL_MINUTE</code> is 4.
+   * @stable ICU 2.6 
+   */
+  UCAL_MINUTE,
+
+ /**
+   * Field number indicating the
+   * second within the minute.
+   * E.g., at 10:04:15.250 PM the <code>UCAL_SECOND</code> is 15.
+   * @stable ICU 2.6 
+   */
+  UCAL_SECOND,
+
+ /**
+   * Field number indicating the
+   * millisecond within the second.
+   * E.g., at 10:04:15.250 PM the <code>UCAL_MILLISECOND</code> is 250.
+   * @stable ICU 2.6 
+   */
+  UCAL_MILLISECOND,
+
+ /**
+   * Field number indicating the
+   * raw offset from GMT in milliseconds.
+   * @stable ICU 2.6 
+   */
+  UCAL_ZONE_OFFSET,
+
+ /**
+   * Field number indicating the
+   * daylight savings offset in milliseconds.
+   * @stable ICU 2.6 
+   */
+  UCAL_DST_OFFSET,
+  
+ /**
+   * Field number 
+   * indicating the extended year corresponding to the
+   * <code>UCAL_WEEK_OF_YEAR</code> field.  This may be one greater or less
+   * than the value of <code>UCAL_EXTENDED_YEAR</code>.
+   * @stable ICU 2.6
+   */
+  UCAL_YEAR_WOY,
+
+ /**
+   * Field number 
+   * indicating the localized day of week.  This will be a value from 1
+   * to 7 inclusive, with 1 being the localized first day of the week.
+   * @stable ICU 2.6
+   */
+  UCAL_DOW_LOCAL,
+
+  /**
+   * Year of this calendar system, encompassing all supra-year fields. For example, 
+   * in Gregorian/Julian calendars, positive Extended Year values indicate years AD,
+   *  1 BC = 0 extended, 2 BC = -1 extended, and so on. 
+   * @stable ICU 2.8 
+   */
+  UCAL_EXTENDED_YEAR,
+
+ /**
+   * Field number 
+   * indicating the modified Julian day number.  This is different from
+   * the conventional Julian day number in two regards.  First, it
+   * demarcates days at local zone midnight, rather than noon GMT.
+   * Second, it is a local number; that is, it depends on the local time
+   * zone.  It can be thought of as a single number that encompasses all
+   * the date-related fields.
+   * @stable ICU 2.8
+   */
+  UCAL_JULIAN_DAY, 
+
+  /**
+   * Ranges from 0 to 23:59:59.999 (regardless of DST).  This field behaves <em>exactly</em> 
+   * like a composite of all time-related fields, not including the zone fields.  As such, 
+   * it also reflects discontinuities of those fields on DST transition days.  On a day
+   * of DST onset, it will jump forward.  On a day of DST cessation, it will jump 
+   * backward.  This reflects the fact that it must be combined with the DST_OFFSET field
+   * to obtain a unique local time value.
+   * @stable ICU 2.8
+   */
+  UCAL_MILLISECONDS_IN_DAY,
+
+  /**
+   * Whether or not the current month is a leap month (0 or 1). See the Chinese calendar for
+   * an example of this.
+   */
+  UCAL_IS_LEAP_MONTH,
+
+    /* Do not conditionalize the following with #ifndef U_HIDE_DEPRECATED_API,
+     * it is needed for layout of Calendar, DateFormat, and other objects */
+#ifndef U_FORCE_HIDE_DEPRECATED_API
+    /**
+     * One more than the highest normal UCalendarDateFields value.
+     * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
+     */
+    UCAL_FIELD_COUNT,
+#endif  // U_FORCE_HIDE_DEPRECATED_API
+
+ /**
+   * Field number indicating the
+   * day of the month. This is a synonym for <code>UCAL_DATE</code>.
+   * The first day of the month has value 1.
+   * @see #UCAL_DATE
+   * Synonym for UCAL_DATE
+   * @stable ICU 2.8
+   **/
+  UCAL_DAY_OF_MONTH=UCAL_DATE
+};
+
+/** @stable ICU 2.0 */
+typedef enum UCalendarDateFields UCalendarDateFields;
+    /**
+     * Useful constant for days of week. Note: Calendar day-of-week is 1-based. Clients
+     * who create locale resources for the field of first-day-of-week should be aware of
+     * this. For instance, in US locale, first-day-of-week is set to 1, i.e., UCAL_SUNDAY.
+     */
+/** Possible days of the week in a UCalendar 
+ * @stable ICU 2.0
+ */
+enum UCalendarDaysOfWeek {
+  /** Sunday */
+  UCAL_SUNDAY = 1,
+  /** Monday */
+  UCAL_MONDAY,
+  /** Tuesday */
+  UCAL_TUESDAY,
+  /** Wednesday */
+  UCAL_WEDNESDAY,
+  /** Thursday */
+  UCAL_THURSDAY,
+  /** Friday */
+  UCAL_FRIDAY,
+  /** Saturday */
+  UCAL_SATURDAY
+};
+
+/** @stable ICU 2.0 */
+typedef enum UCalendarDaysOfWeek UCalendarDaysOfWeek;
+
+/** Possible months in a UCalendar. Note: Calendar month is 0-based.
+ * @stable ICU 2.0
+ */
+enum UCalendarMonths {
+  /** January */
+  UCAL_JANUARY,
+  /** February */
+  UCAL_FEBRUARY,
+  /** March */
+  UCAL_MARCH,
+  /** April */
+  UCAL_APRIL,
+  /** May */
+  UCAL_MAY,
+  /** June */
+  UCAL_JUNE,
+  /** July */
+  UCAL_JULY,
+  /** August */
+  UCAL_AUGUST,
+  /** September */
+  UCAL_SEPTEMBER,
+  /** October */
+  UCAL_OCTOBER,
+  /** November */
+  UCAL_NOVEMBER,
+  /** December */
+  UCAL_DECEMBER,
+  /** Value of the <code>UCAL_MONTH</code> field indicating the
+    * thirteenth month of the year. Although the Gregorian calendar
+    * does not use this value, lunar calendars do.
+    */
+  UCAL_UNDECIMBER
+};
+
+/** @stable ICU 2.0 */
+typedef enum UCalendarMonths UCalendarMonths;
+
+/** Possible AM/PM values in a UCalendar 
+ * @stable ICU 2.0
+ */
+enum UCalendarAMPMs {
+    /** AM */
+  UCAL_AM,
+  /** PM */
+  UCAL_PM
+};
+
+/** @stable ICU 2.0 */
+typedef enum UCalendarAMPMs UCalendarAMPMs;
+
+/**
+ * System time zone type constants used by filtering zones
+ * in ucal_openTimeZoneIDEnumeration.
+ * @see ucal_openTimeZoneIDEnumeration
+ * @stable ICU 4.8
+ */
+enum USystemTimeZoneType {
+    /**
+     * Any system zones.
+     * @stable ICU 4.8
+     */
+    UCAL_ZONE_TYPE_ANY,
+    /**
+     * Canonical system zones.
+     * @stable ICU 4.8
+     */
+    UCAL_ZONE_TYPE_CANONICAL,
+    /**
+     * Canonical system zones associated with actual locations.
+     * @stable ICU 4.8
+     */
+    UCAL_ZONE_TYPE_CANONICAL_LOCATION
+};
+
+/** @stable ICU 4.8 */
+typedef enum USystemTimeZoneType USystemTimeZoneType;
+
+/** 
+ * Create an enumeration over system time zone IDs with the given
+ * filter conditions. 
+ * @param zoneType  The system time zone type.
+ * @param region    The ISO 3166 two-letter country code or UN M.49
+ *                  three-digit area code.  When NULL, no filtering
+ *                  done by region. 
+ * @param rawOffset An offset from GMT in milliseconds, ignoring the
+ *                  effect of daylight savings time, if any. When NULL,
+ *                  no filtering done by zone offset.
+ * @param ec        A pointer to an UErrorCode to receive any errors
+ * @return  an enumeration object that the caller must dispose of
+ *          using enum_close(), or NULL upon failure. In case of failure,
+ *          *ec will indicate the error.
+ * @stable ICU 4.8
+ */ 
+U_STABLE UEnumeration* U_EXPORT2
+ucal_openTimeZoneIDEnumeration(USystemTimeZoneType zoneType, const char* region,
+                                const int32_t* rawOffset, UErrorCode* ec);
+
+/**
+ * Create an enumeration over all time zones.
+ *
+ * @param ec input/output error code
+ *
+ * @return an enumeration object that the caller must dispose of using
+ * uenum_close(), or NULL upon failure. In case of failure *ec will
+ * indicate the error.
+ *
+ * @stable ICU 2.6
+ */
+U_STABLE UEnumeration* U_EXPORT2
+ucal_openTimeZones(UErrorCode* ec);
+
+/**
+ * Create an enumeration over all time zones associated with the given
+ * country. Some zones are affiliated with no country (e.g., "UTC");
+ * these may also be retrieved, as a group.
+ *
+ * @param country the ISO 3166 two-letter country code, or NULL to
+ * retrieve zones not affiliated with any country
+ *
+ * @param ec input/output error code
+ *
+ * @return an enumeration object that the caller must dispose of using
+ * uenum_close(), or NULL upon failure. In case of failure *ec will
+ * indicate the error.
+ *
+ * @stable ICU 2.6
+ */
+U_STABLE UEnumeration* U_EXPORT2
+ucal_openCountryTimeZones(const char* country, UErrorCode* ec);
+
+/**
+ * Return the default time zone. The default is determined initially
+ * by querying the host operating system. If the host system detection
+ * routines fail, or if they specify a TimeZone or TimeZone offset
+ * which is not recognized, then the special TimeZone "Etc/Unknown"
+ * is returned.
+ * 
+ * The default may be changed with `ucal_setDefaultTimeZone()` or with
+ * the C++ TimeZone API, `TimeZone::adoptDefault(TimeZone*)`.
+ *
+ * @param result A buffer to receive the result, or NULL
+ *
+ * @param resultCapacity The capacity of the result buffer
+ *
+ * @param ec input/output error code
+ *
+ * @return The result string length, not including the terminating
+ * null
+ * 
+ * @see #UCAL_UNKNOWN_ZONE_ID
+ * 
+ * @stable ICU 2.6
+ */
+U_STABLE int32_t U_EXPORT2
+ucal_getDefaultTimeZone(UChar* result, int32_t resultCapacity, UErrorCode* ec);
+
+/**
+ * Set the default time zone.
+ *
+ * @param zoneID null-terminated time zone ID
+ *
+ * @param ec input/output error code
+ *
+ * @stable ICU 2.6
+ */
+U_STABLE void U_EXPORT2
+ucal_setDefaultTimeZone(const UChar* zoneID, UErrorCode* ec);
+
+#ifndef U_HIDE_DRAFT_API
+
+/**
+ * Return the current host time zone. The host time zone is detected from
+ * the current host system configuration by querying the host operating
+ * system. If the host system detection routines fail, or if they specify
+ * a TimeZone or TimeZone offset which is not recognized, then the special
+ * TimeZone "Etc/Unknown" is returned.
+ * 
+ * Note that host time zone and the ICU default time zone can be different.
+ * 
+ * The ICU default time zone does not change once initialized unless modified
+ * by calling `ucal_setDefaultTimeZone()` or with the C++ TimeZone API,
+ * `TimeZone::adoptDefault(TimeZone*)`.
+ * 
+ * If the host operating system configuration has changed since ICU has
+ * initialized then the returned value can be different than the ICU default
+ * time zone, even if the default has not changed.
+ *
+ * <p>This function is not thread safe.</p>
+ * 
+ * @param result A buffer to receive the result, or NULL
+ * @param resultCapacity The capacity of the result buffer
+ * @param ec input/output error code
+ * @return The result string length, not including the terminating
+ * null
+ * 
+ * @see #UCAL_UNKNOWN_ZONE_ID
+ * 
+ * @draft ICU 65
+ */
+U_DRAFT int32_t U_EXPORT2
+ucal_getHostTimeZone(UChar *result, int32_t resultCapacity, UErrorCode *ec);
+
+#endif // U_HIDE_DRAFT_API
+
+/**
+ * Return the amount of time in milliseconds that the clock is
+ * advanced during daylight savings time for the given time zone, or
+ * zero if the time zone does not observe daylight savings time.
+ *
+ * @param zoneID null-terminated time zone ID
+ *
+ * @param ec input/output error code
+ *
+ * @return the number of milliseconds the time is advanced with
+ * respect to standard time when the daylight savings rules are in
+ * effect. This is always a non-negative number, most commonly either
+ * 3,600,000 (one hour) or zero.
+ *
+ * @stable ICU 2.6
+ */
+U_STABLE int32_t U_EXPORT2
+ucal_getDSTSavings(const UChar* zoneID, UErrorCode* ec);
+
+/**
+ * Get the current date and time.
+ * The value returned is represented as milliseconds from the epoch.
+ * @return The current date and time.
+ * @stable ICU 2.0
+ */
+U_STABLE UDate U_EXPORT2 
+ucal_getNow(void);
+
+/**
+ * Open a UCalendar.
+ * A UCalendar may be used to convert a millisecond value to a year,
+ * month, and day.
+ * <p>
+ * Note: When unknown TimeZone ID is specified or if the TimeZone ID specified is "Etc/Unknown",
+ * the UCalendar returned by the function is initialized with GMT zone with TimeZone ID
+ * <code>UCAL_UNKNOWN_ZONE_ID</code> ("Etc/Unknown") without any errors/warnings.  If you want
+ * to check if a TimeZone ID is valid prior to this function, use <code>ucal_getCanonicalTimeZoneID</code>.
+ * 
+ * @param zoneID The desired TimeZone ID.  If 0, use the default time zone.
+ * @param len The length of zoneID, or -1 if null-terminated.
+ * @param locale The desired locale
+ * @param type The type of UCalendar to open. This can be UCAL_GREGORIAN to open the Gregorian
+ * calendar for the locale, or UCAL_DEFAULT to open the default calendar for the locale (the
+ * default calendar may also be Gregorian). To open a specific non-Gregorian calendar for the
+ * locale, use uloc_setKeywordValue to set the value of the calendar keyword for the locale
+ * and then pass the locale to ucal_open with UCAL_DEFAULT as the type.
+ * @param status A pointer to an UErrorCode to receive any errors
+ * @return A pointer to a UCalendar, or 0 if an error occurred.
+ * @see #UCAL_UNKNOWN_ZONE_ID
+ * @stable ICU 2.0
+ */
+U_STABLE UCalendar* U_EXPORT2 
+ucal_open(const UChar*   zoneID,
+          int32_t        len,
+          const char*    locale,
+          UCalendarType  type,
+          UErrorCode*    status);
+
+/**
+ * Close a UCalendar.
+ * Once closed, a UCalendar may no longer be used.
+ * @param cal The UCalendar to close.
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+ucal_close(UCalendar *cal);
+
+#if U_SHOW_CPLUSPLUS_API
+
+U_NAMESPACE_BEGIN
+
+/**
+ * \class LocalUCalendarPointer
+ * "Smart pointer" class, closes a UCalendar via ucal_close().
+ * For most methods see the LocalPointerBase base class.
+ *
+ * @see LocalPointerBase
+ * @see LocalPointer
+ * @stable ICU 4.4
+ */
+U_DEFINE_LOCAL_OPEN_POINTER(LocalUCalendarPointer, UCalendar, ucal_close);
+
+U_NAMESPACE_END
+
+#endif
+
+/**
+ * Open a copy of a UCalendar.
+ * This function performs a deep copy.
+ * @param cal The calendar to copy
+ * @param status A pointer to an UErrorCode to receive any errors.
+ * @return A pointer to a UCalendar identical to cal.
+ * @stable ICU 4.0
+ */
+U_STABLE UCalendar* U_EXPORT2 
+ucal_clone(const UCalendar* cal,
+           UErrorCode*      status);
+
+/**
+ * Set the TimeZone used by a UCalendar.
+ * A UCalendar uses a timezone for converting from Greenwich time to local time.
+ * @param cal The UCalendar to set.
+ * @param zoneID The desired TimeZone ID.  If 0, use the default time zone.
+ * @param len The length of zoneID, or -1 if null-terminated.
+ * @param status A pointer to an UErrorCode to receive any errors.
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+ucal_setTimeZone(UCalendar*    cal,
+                 const UChar*  zoneID,
+                 int32_t       len,
+                 UErrorCode*   status);
+
+/** 
+ * Get the ID of the UCalendar's time zone. 
+ * 
+ * @param cal           The UCalendar to query. 
+ * @param result        Receives the UCalendar's time zone ID. 
+ * @param resultLength  The maximum size of result. 
+ * @param status        Receives the status. 
+ * @return              The total buffer size needed; if greater than resultLength, the output was truncated. 
+ * @stable ICU 51 
+ */ 
+U_STABLE int32_t U_EXPORT2 
+ucal_getTimeZoneID(const UCalendar *cal,
+                   UChar *result,
+                   int32_t resultLength,
+                   UErrorCode *status);
+
+/**
+ * Possible formats for a UCalendar's display name 
+ * @stable ICU 2.0
+ */
+enum UCalendarDisplayNameType {
+  /** Standard display name */
+  UCAL_STANDARD,
+  /** Short standard display name */
+  UCAL_SHORT_STANDARD,
+  /** Daylight savings display name */
+  UCAL_DST,
+  /** Short daylight savings display name */
+  UCAL_SHORT_DST
+};
+
+/** @stable ICU 2.0 */
+typedef enum UCalendarDisplayNameType UCalendarDisplayNameType;
+
+/**
+ * Get the display name for a UCalendar's TimeZone.
+ * A display name is suitable for presentation to a user.
+ * @param cal          The UCalendar to query.
+ * @param type         The desired display name format; one of UCAL_STANDARD, UCAL_SHORT_STANDARD,
+ *                     UCAL_DST, UCAL_SHORT_DST
+ * @param locale       The desired locale for the display name.
+ * @param result       A pointer to a buffer to receive the formatted number.
+ * @param resultLength The maximum size of result.
+ * @param status       A pointer to an UErrorCode to receive any errors
+ * @return             The total buffer size needed; if greater than resultLength, the output was truncated.
+ * @stable ICU 2.0
+ */
+U_STABLE int32_t U_EXPORT2 
+ucal_getTimeZoneDisplayName(const UCalendar*          cal,
+                            UCalendarDisplayNameType  type,
+                            const char*               locale,
+                            UChar*                    result,
+                            int32_t                   resultLength,
+                            UErrorCode*               status);
+
+/**
+ * Determine if a UCalendar is currently in daylight savings time.
+ * Daylight savings time is not used in all parts of the world.
+ * @param cal The UCalendar to query.
+ * @param status A pointer to an UErrorCode to receive any errors
+ * @return TRUE if cal is currently in daylight savings time, FALSE otherwise
+ * @stable ICU 2.0
+ */
+U_STABLE UBool U_EXPORT2 
+ucal_inDaylightTime(const UCalendar*  cal,
+                    UErrorCode*       status );
+
+/**
+ * Sets the GregorianCalendar change date. This is the point when the switch from
+ * Julian dates to Gregorian dates occurred. Default is 00:00:00 local time, October
+ * 15, 1582. Previous to this time and date will be Julian dates.
+ *
+ * This function works only for Gregorian calendars. If the UCalendar is not
+ * an instance of a Gregorian calendar, then a U_UNSUPPORTED_ERROR
+ * error code is set.
+ *
+ * @param cal        The calendar object.
+ * @param date       The given Gregorian cutover date.
+ * @param pErrorCode Pointer to a standard ICU error code. Its input value must
+ *                   pass the U_SUCCESS() test, or else the function returns
+ *                   immediately. Check for U_FAILURE() on output or use with
+ *                   function chaining. (See User Guide for details.)
+ *
+ * @see GregorianCalendar::setGregorianChange
+ * @see ucal_getGregorianChange
+ * @stable ICU 3.6
+ */
+U_STABLE void U_EXPORT2
+ucal_setGregorianChange(UCalendar *cal, UDate date, UErrorCode *pErrorCode);
+
+/**
+ * Gets the Gregorian Calendar change date. This is the point when the switch from
+ * Julian dates to Gregorian dates occurred. Default is 00:00:00 local time, October
+ * 15, 1582. Previous to this time and date will be Julian dates.
+ *
+ * This function works only for Gregorian calendars. If the UCalendar is not
+ * an instance of a Gregorian calendar, then a U_UNSUPPORTED_ERROR
+ * error code is set.
+ *
+ * @param cal        The calendar object.
+ * @param pErrorCode Pointer to a standard ICU error code. Its input value must
+ *                   pass the U_SUCCESS() test, or else the function returns
+ *                   immediately. Check for U_FAILURE() on output or use with
+ *                   function chaining. (See User Guide for details.)
+ * @return   The Gregorian cutover time for this calendar.
+ *
+ * @see GregorianCalendar::getGregorianChange
+ * @see ucal_setGregorianChange
+ * @stable ICU 3.6
+ */
+U_STABLE UDate U_EXPORT2
+ucal_getGregorianChange(const UCalendar *cal, UErrorCode *pErrorCode);
+
+/**
+ * Types of UCalendar attributes 
+ * @stable ICU 2.0
+ */
+enum UCalendarAttribute {
+  /**
+   * Lenient parsing
+   * @stable ICU 2.0
+   */
+  UCAL_LENIENT,
+  /**
+   * First day of week
+   * @stable ICU 2.0
+   */
+  UCAL_FIRST_DAY_OF_WEEK,
+  /**
+   * Minimum number of days in first week
+   * @stable ICU 2.0
+   */
+  UCAL_MINIMAL_DAYS_IN_FIRST_WEEK,
+  /**
+   * The behavior for handling wall time repeating multiple times
+   * at negative time zone offset transitions
+   * @stable ICU 49
+   */
+  UCAL_REPEATED_WALL_TIME,
+  /**
+   * The behavior for handling skipped wall time at positive time
+   * zone offset transitions.
+   * @stable ICU 49
+   */
+  UCAL_SKIPPED_WALL_TIME
+};
+
+/** @stable ICU 2.0 */
+typedef enum UCalendarAttribute UCalendarAttribute;
+
+/**
+ * Options for handling ambiguous wall time at time zone
+ * offset transitions.
+ * @stable ICU 49
+ */
+enum UCalendarWallTimeOption {
+    /**
+     * An ambiguous wall time to be interpreted as the latest.
+     * This option is valid for UCAL_REPEATED_WALL_TIME and
+     * UCAL_SKIPPED_WALL_TIME.
+     * @stable ICU 49
+     */
+    UCAL_WALLTIME_LAST,
+    /**
+     * An ambiguous wall time to be interpreted as the earliest.
+     * This option is valid for UCAL_REPEATED_WALL_TIME and
+     * UCAL_SKIPPED_WALL_TIME.
+     * @stable ICU 49
+     */
+    UCAL_WALLTIME_FIRST,
+    /**
+     * An ambiguous wall time to be interpreted as the next valid
+     * wall time. This option is valid for UCAL_SKIPPED_WALL_TIME.
+     * @stable ICU 49
+     */
+    UCAL_WALLTIME_NEXT_VALID
+};
+/** @stable ICU 49 */
+typedef enum UCalendarWallTimeOption UCalendarWallTimeOption;
+
+/**
+ * Get a numeric attribute associated with a UCalendar.
+ * Numeric attributes include the first day of the week, or the minimal numbers
+ * of days in the first week of the month.
+ * @param cal The UCalendar to query.
+ * @param attr The desired attribute; one of UCAL_LENIENT, UCAL_FIRST_DAY_OF_WEEK,
+ * UCAL_MINIMAL_DAYS_IN_FIRST_WEEK, UCAL_REPEATED_WALL_TIME or UCAL_SKIPPED_WALL_TIME
+ * @return The value of attr.
+ * @see ucal_setAttribute
+ * @stable ICU 2.0
+ */
+U_STABLE int32_t U_EXPORT2 
+ucal_getAttribute(const UCalendar*    cal,
+                  UCalendarAttribute  attr);
+
+/**
+ * Set a numeric attribute associated with a UCalendar.
+ * Numeric attributes include the first day of the week, or the minimal numbers
+ * of days in the first week of the month.
+ * @param cal The UCalendar to set.
+ * @param attr The desired attribute; one of UCAL_LENIENT, UCAL_FIRST_DAY_OF_WEEK,
+ * UCAL_MINIMAL_DAYS_IN_FIRST_WEEK, UCAL_REPEATED_WALL_TIME or UCAL_SKIPPED_WALL_TIME
+ * @param newValue The new value of attr.
+ * @see ucal_getAttribute
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+ucal_setAttribute(UCalendar*          cal,
+                  UCalendarAttribute  attr,
+                  int32_t             newValue);
+
+/**
+ * Get a locale for which calendars are available.
+ * A UCalendar in a locale returned by this function will contain the correct
+ * day and month names for the locale.
+ * @param localeIndex The index of the desired locale.
+ * @return A locale for which calendars are available, or 0 if none.
+ * @see ucal_countAvailable
+ * @stable ICU 2.0
+ */
+U_STABLE const char* U_EXPORT2 
+ucal_getAvailable(int32_t localeIndex);
+
+/**
+ * Determine how many locales have calendars available.
+ * This function is most useful as determining the loop ending condition for
+ * calls to \ref ucal_getAvailable.
+ * @return The number of locales for which calendars are available.
+ * @see ucal_getAvailable
+ * @stable ICU 2.0
+ */
+U_STABLE int32_t U_EXPORT2 
+ucal_countAvailable(void);
+
+/**
+ * Get a UCalendar's current time in millis.
+ * The time is represented as milliseconds from the epoch.
+ * @param cal The UCalendar to query.
+ * @param status A pointer to an UErrorCode to receive any errors
+ * @return The calendar's current time in millis.
+ * @see ucal_setMillis
+ * @see ucal_setDate
+ * @see ucal_setDateTime
+ * @stable ICU 2.0
+ */
+U_STABLE UDate U_EXPORT2 
+ucal_getMillis(const UCalendar*  cal,
+               UErrorCode*       status);
+
+/**
+ * Set a UCalendar's current time in millis.
+ * The time is represented as milliseconds from the epoch.
+ * @param cal The UCalendar to set.
+ * @param dateTime The desired date and time.
+ * @param status A pointer to an UErrorCode to receive any errors
+ * @see ucal_getMillis
+ * @see ucal_setDate
+ * @see ucal_setDateTime
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+ucal_setMillis(UCalendar*   cal,
+               UDate        dateTime,
+               UErrorCode*  status );
+
+/**
+ * Set a UCalendar's current date.
+ * The date is represented as a series of 32-bit integers.
+ * @param cal The UCalendar to set.
+ * @param year The desired year.
+ * @param month The desired month; one of UCAL_JANUARY, UCAL_FEBRUARY, UCAL_MARCH, UCAL_APRIL, UCAL_MAY,
+ * UCAL_JUNE, UCAL_JULY, UCAL_AUGUST, UCAL_SEPTEMBER, UCAL_OCTOBER, UCAL_NOVEMBER, UCAL_DECEMBER, UCAL_UNDECIMBER
+ * @param date The desired day of the month.
+ * @param status A pointer to an UErrorCode to receive any errors
+ * @see ucal_getMillis
+ * @see ucal_setMillis
+ * @see ucal_setDateTime
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+ucal_setDate(UCalendar*   cal,
+             int32_t      year,
+             int32_t      month,
+             int32_t      date,
+             UErrorCode*  status);
+
+/**
+ * Set a UCalendar's current date.
+ * The date is represented as a series of 32-bit integers.
+ * @param cal The UCalendar to set.
+ * @param year The desired year.
+ * @param month The desired month; one of UCAL_JANUARY, UCAL_FEBRUARY, UCAL_MARCH, UCAL_APRIL, UCAL_MAY,
+ * UCAL_JUNE, UCAL_JULY, UCAL_AUGUST, UCAL_SEPTEMBER, UCAL_OCTOBER, UCAL_NOVEMBER, UCAL_DECEMBER, UCAL_UNDECIMBER
+ * @param date The desired day of the month.
+ * @param hour The desired hour of day.
+ * @param minute The desired minute.
+ * @param second The desirec second.
+ * @param status A pointer to an UErrorCode to receive any errors
+ * @see ucal_getMillis
+ * @see ucal_setMillis
+ * @see ucal_setDate
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+ucal_setDateTime(UCalendar*   cal,
+                 int32_t      year,
+                 int32_t      month,
+                 int32_t      date,
+                 int32_t      hour,
+                 int32_t      minute,
+                 int32_t      second,
+                 UErrorCode*  status);
+
+/**
+ * Returns TRUE if two UCalendars are equivalent.  Equivalent
+ * UCalendars will behave identically, but they may be set to
+ * different times.
+ * @param cal1 The first of the UCalendars to compare.
+ * @param cal2 The second of the UCalendars to compare.
+ * @return TRUE if cal1 and cal2 are equivalent, FALSE otherwise.
+ * @stable ICU 2.0
+ */
+U_STABLE UBool U_EXPORT2 
+ucal_equivalentTo(const UCalendar*  cal1,
+                  const UCalendar*  cal2);
+
+/**
+ * Add a specified signed amount to a particular field in a UCalendar.
+ * This can modify more significant fields in the calendar.
+ * Adding a positive value always means moving forward in time, so for the Gregorian calendar,
+ * starting with 100 BC and adding +1 to year results in 99 BC (even though this actually reduces
+ * the numeric value of the field itself).
+ * @param cal The UCalendar to which to add.
+ * @param field The field to which to add the signed value; one of UCAL_ERA, UCAL_YEAR, UCAL_MONTH,
+ * UCAL_WEEK_OF_YEAR, UCAL_WEEK_OF_MONTH, UCAL_DATE, UCAL_DAY_OF_YEAR, UCAL_DAY_OF_WEEK,
+ * UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_AM_PM, UCAL_HOUR, UCAL_HOUR_OF_DAY, UCAL_MINUTE, UCAL_SECOND,
+ * UCAL_MILLISECOND, UCAL_ZONE_OFFSET, UCAL_DST_OFFSET.
+ * @param amount The signed amount to add to field. If the amount causes the value
+ * to exceed to maximum or minimum values for that field, other fields are modified
+ * to preserve the magnitude of the change.
+ * @param status A pointer to an UErrorCode to receive any errors
+ * @see ucal_roll
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+ucal_add(UCalendar*           cal,
+         UCalendarDateFields  field,
+         int32_t              amount,
+         UErrorCode*          status);
+
+/**
+ * Add a specified signed amount to a particular field in a UCalendar.
+ * This will not modify more significant fields in the calendar.
+ * Rolling by a positive value always means moving forward in time (unless the limit of the
+ * field is reached, in which case it may pin or wrap), so for Gregorian calendar,
+ * starting with 100 BC and rolling the year by +1 results in 99 BC.
+ * When eras have a definite beginning and end (as in the Chinese calendar, or as in most eras in the
+ * Japanese calendar) then rolling the year past either limit of the era will cause the year to wrap around.
+ * When eras only have a limit at one end, then attempting to roll the year past that limit will result in
+ * pinning the year at that limit. Note that for most calendars in which era 0 years move forward in time
+ * (such as Buddhist, Hebrew, or Islamic), it is possible for add or roll to result in negative years for
+ * era 0 (that is the only way to represent years before the calendar epoch).
+ * @param cal The UCalendar to which to add.
+ * @param field The field to which to add the signed value; one of UCAL_ERA, UCAL_YEAR, UCAL_MONTH,
+ * UCAL_WEEK_OF_YEAR, UCAL_WEEK_OF_MONTH, UCAL_DATE, UCAL_DAY_OF_YEAR, UCAL_DAY_OF_WEEK,
+ * UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_AM_PM, UCAL_HOUR, UCAL_HOUR_OF_DAY, UCAL_MINUTE, UCAL_SECOND,
+ * UCAL_MILLISECOND, UCAL_ZONE_OFFSET, UCAL_DST_OFFSET.
+ * @param amount The signed amount to add to field. If the amount causes the value
+ * to exceed to maximum or minimum values for that field, the field is pinned to a permissible
+ * value.
+ * @param status A pointer to an UErrorCode to receive any errors
+ * @see ucal_add
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+ucal_roll(UCalendar*           cal,
+          UCalendarDateFields  field,
+          int32_t              amount,
+          UErrorCode*          status);
+
+/**
+ * Get the current value of a field from a UCalendar.
+ * All fields are represented as 32-bit integers.
+ * @param cal The UCalendar to query.
+ * @param field The desired field; one of UCAL_ERA, UCAL_YEAR, UCAL_MONTH,
+ * UCAL_WEEK_OF_YEAR, UCAL_WEEK_OF_MONTH, UCAL_DATE, UCAL_DAY_OF_YEAR, UCAL_DAY_OF_WEEK,
+ * UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_AM_PM, UCAL_HOUR, UCAL_HOUR_OF_DAY, UCAL_MINUTE, UCAL_SECOND,
+ * UCAL_MILLISECOND, UCAL_ZONE_OFFSET, UCAL_DST_OFFSET.
+ * @param status A pointer to an UErrorCode to receive any errors
+ * @return The value of the desired field.
+ * @see ucal_set
+ * @see ucal_isSet
+ * @see ucal_clearField
+ * @see ucal_clear
+ * @stable ICU 2.0
+ */
+U_STABLE int32_t U_EXPORT2 
+ucal_get(const UCalendar*     cal,
+         UCalendarDateFields  field,
+         UErrorCode*          status );
+
+/**
+ * Set the value of a field in a UCalendar.
+ * All fields are represented as 32-bit integers.
+ * @param cal The UCalendar to set.
+ * @param field The field to set; one of UCAL_ERA, UCAL_YEAR, UCAL_MONTH,
+ * UCAL_WEEK_OF_YEAR, UCAL_WEEK_OF_MONTH, UCAL_DATE, UCAL_DAY_OF_YEAR, UCAL_DAY_OF_WEEK,
+ * UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_AM_PM, UCAL_HOUR, UCAL_HOUR_OF_DAY, UCAL_MINUTE, UCAL_SECOND,
+ * UCAL_MILLISECOND, UCAL_ZONE_OFFSET, UCAL_DST_OFFSET.
+ * @param value The desired value of field.
+ * @see ucal_get
+ * @see ucal_isSet
+ * @see ucal_clearField
+ * @see ucal_clear
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+ucal_set(UCalendar*           cal,
+         UCalendarDateFields  field,
+         int32_t              value);
+
+/**
+ * Determine if a field in a UCalendar is set.
+ * All fields are represented as 32-bit integers.
+ * @param cal The UCalendar to query.
+ * @param field The desired field; one of UCAL_ERA, UCAL_YEAR, UCAL_MONTH,
+ * UCAL_WEEK_OF_YEAR, UCAL_WEEK_OF_MONTH, UCAL_DATE, UCAL_DAY_OF_YEAR, UCAL_DAY_OF_WEEK,
+ * UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_AM_PM, UCAL_HOUR, UCAL_HOUR_OF_DAY, UCAL_MINUTE, UCAL_SECOND,
+ * UCAL_MILLISECOND, UCAL_ZONE_OFFSET, UCAL_DST_OFFSET.
+ * @return TRUE if field is set, FALSE otherwise.
+ * @see ucal_get
+ * @see ucal_set
+ * @see ucal_clearField
+ * @see ucal_clear
+ * @stable ICU 2.0
+ */
+U_STABLE UBool U_EXPORT2 
+ucal_isSet(const UCalendar*     cal,
+           UCalendarDateFields  field);
+
+/**
+ * Clear a field in a UCalendar.
+ * All fields are represented as 32-bit integers.
+ * @param cal The UCalendar containing the field to clear.
+ * @param field The field to clear; one of UCAL_ERA, UCAL_YEAR, UCAL_MONTH,
+ * UCAL_WEEK_OF_YEAR, UCAL_WEEK_OF_MONTH, UCAL_DATE, UCAL_DAY_OF_YEAR, UCAL_DAY_OF_WEEK,
+ * UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_AM_PM, UCAL_HOUR, UCAL_HOUR_OF_DAY, UCAL_MINUTE, UCAL_SECOND,
+ * UCAL_MILLISECOND, UCAL_ZONE_OFFSET, UCAL_DST_OFFSET.
+ * @see ucal_get
+ * @see ucal_set
+ * @see ucal_isSet
+ * @see ucal_clear
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+ucal_clearField(UCalendar*           cal,
+                UCalendarDateFields  field);
+
+/**
+ * Clear all fields in a UCalendar.
+ * All fields are represented as 32-bit integers.
+ * @param calendar The UCalendar to clear.
+ * @see ucal_get
+ * @see ucal_set
+ * @see ucal_isSet
+ * @see ucal_clearField
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2 
+ucal_clear(UCalendar* calendar);
+
+/**
+ * Possible limit values for a UCalendar 
+ * @stable ICU 2.0
+ */
+enum UCalendarLimitType {
+  /** Minimum value */
+  UCAL_MINIMUM,
+  /** Maximum value */
+  UCAL_MAXIMUM,
+  /** Greatest minimum value */
+  UCAL_GREATEST_MINIMUM,
+  /** Leaest maximum value */
+  UCAL_LEAST_MAXIMUM,
+  /** Actual minimum value */
+  UCAL_ACTUAL_MINIMUM,
+  /** Actual maximum value */
+  UCAL_ACTUAL_MAXIMUM
+};
+
+/** @stable ICU 2.0 */
+typedef enum UCalendarLimitType UCalendarLimitType;
+
+/**
+ * Determine a limit for a field in a UCalendar.
+ * A limit is a maximum or minimum value for a field.
+ * @param cal The UCalendar to query.
+ * @param field The desired field; one of UCAL_ERA, UCAL_YEAR, UCAL_MONTH,
+ * UCAL_WEEK_OF_YEAR, UCAL_WEEK_OF_MONTH, UCAL_DATE, UCAL_DAY_OF_YEAR, UCAL_DAY_OF_WEEK,
+ * UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_AM_PM, UCAL_HOUR, UCAL_HOUR_OF_DAY, UCAL_MINUTE, UCAL_SECOND,
+ * UCAL_MILLISECOND, UCAL_ZONE_OFFSET, UCAL_DST_OFFSET.
+ * @param type The desired critical point; one of UCAL_MINIMUM, UCAL_MAXIMUM, UCAL_GREATEST_MINIMUM,
+ * UCAL_LEAST_MAXIMUM, UCAL_ACTUAL_MINIMUM, UCAL_ACTUAL_MAXIMUM
+ * @param status A pointer to an UErrorCode to receive any errors.
+ * @return The requested value.
+ * @stable ICU 2.0
+ */
+U_STABLE int32_t U_EXPORT2 
+ucal_getLimit(const UCalendar*     cal,
+              UCalendarDateFields  field,
+              UCalendarLimitType   type,
+              UErrorCode*          status);
+
+/** Get the locale for this calendar object. You can choose between valid and actual locale.
+ *  @param cal The calendar object
+ *  @param type type of the locale we're looking for (valid or actual) 
+ *  @param status error code for the operation
+ *  @return the locale name
+ *  @stable ICU 2.8
+ */
+U_STABLE const char * U_EXPORT2
+ucal_getLocaleByType(const UCalendar *cal, ULocDataLocaleType type, UErrorCode* status);
+
+/**
+ * Returns the timezone data version currently used by ICU.
+ * @param status error code for the operation
+ * @return the version string, such as "2007f"
+ * @stable ICU 3.8
+ */
+U_STABLE const char * U_EXPORT2
+ucal_getTZDataVersion(UErrorCode* status);
+
+/**
+ * Returns the canonical system timezone ID or the normalized
+ * custom time zone ID for the given time zone ID.
+ * @param id        The input timezone ID to be canonicalized.
+ * @param len       The length of id, or -1 if null-terminated.
+ * @param result    The buffer receives the canonical system timezone ID
+ *                  or the custom timezone ID in normalized format.
+ * @param resultCapacity    The capacity of the result buffer.
+ * @param isSystemID        Receives if the given ID is a known system
+     *                      timezone ID.
+ * @param status    Receives the status.  When the given timezone ID
+ *                  is neither a known system time zone ID nor a
+ *                  valid custom timezone ID, U_ILLEGAL_ARGUMENT_ERROR
+ *                  is set.
+ * @return          The result string length, not including the terminating
+ *                  null.
+ * @stable ICU 4.0
+ */
+U_STABLE int32_t U_EXPORT2
+ucal_getCanonicalTimeZoneID(const UChar* id, int32_t len,
+                            UChar* result, int32_t resultCapacity, UBool *isSystemID, UErrorCode* status);
+/**
+ * Get the resource keyword value string designating the calendar type for the UCalendar.
+ * @param cal The UCalendar to query.
+ * @param status The error code for the operation.
+ * @return The resource keyword value string.
+ * @stable ICU 4.2
+ */
+U_STABLE const char * U_EXPORT2
+ucal_getType(const UCalendar *cal, UErrorCode* status);
+
+/**
+ * Given a key and a locale, returns an array of string values in a preferred
+ * order that would make a difference. These are all and only those values where
+ * the open (creation) of the service with the locale formed from the input locale
+ * plus input keyword and that value has different behavior than creation with the
+ * input locale alone.
+ * @param key           one of the keys supported by this service.  For now, only
+ *                      "calendar" is supported.
+ * @param locale        the locale
+ * @param commonlyUsed  if set to true it will return only commonly used values
+ *                      with the given locale in preferred order.  Otherwise,
+ *                      it will return all the available values for the locale.
+ * @param status error status
+ * @return a string enumeration over keyword values for the given key and the locale.
+ * @stable ICU 4.2
+ */
+U_STABLE UEnumeration* U_EXPORT2
+ucal_getKeywordValuesForLocale(const char* key,
+                               const char* locale,
+                               UBool commonlyUsed,
+                               UErrorCode* status);
+
+
+/** Weekday types, as returned by ucal_getDayOfWeekType().
+ * @stable ICU 4.4
+ */
+enum UCalendarWeekdayType {
+  /**
+   * Designates a full weekday (no part of the day is included in the weekend).
+   * @stable ICU 4.4 
+   */
+  UCAL_WEEKDAY,
+  /**
+   * Designates a full weekend day (the entire day is included in the weekend).
+   * @stable ICU 4.4 
+   */
+  UCAL_WEEKEND,
+  /**
+   * Designates a day that starts as a weekday and transitions to the weekend.
+   * Call ucal_getWeekendTransition() to get the time of transition.
+   * @stable ICU 4.4 
+   */
+  UCAL_WEEKEND_ONSET,
+  /**
+   * Designates a day that starts as the weekend and transitions to a weekday.
+   * Call ucal_getWeekendTransition() to get the time of transition.
+   * @stable ICU 4.4 
+   */
+  UCAL_WEEKEND_CEASE
+};
+
+/** @stable ICU 4.4 */
+typedef enum UCalendarWeekdayType UCalendarWeekdayType;
+
+/**
+ * Returns whether the given day of the week is a weekday, a weekend day,
+ * or a day that transitions from one to the other, for the locale and
+ * calendar system associated with this UCalendar (the locale's region is
+ * often the most determinant factor). If a transition occurs at midnight,
+ * then the days before and after the transition will have the
+ * type UCAL_WEEKDAY or UCAL_WEEKEND. If a transition occurs at a time
+ * other than midnight, then the day of the transition will have
+ * the type UCAL_WEEKEND_ONSET or UCAL_WEEKEND_CEASE. In this case, the
+ * function ucal_getWeekendTransition() will return the point of
+ * transition.
+ * @param cal The UCalendar to query.
+ * @param dayOfWeek The day of the week whose type is desired (UCAL_SUNDAY..UCAL_SATURDAY).
+ * @param status The error code for the operation.
+ * @return The UCalendarWeekdayType for the day of the week.
+ * @stable ICU 4.4
+ */
+U_STABLE UCalendarWeekdayType U_EXPORT2
+ucal_getDayOfWeekType(const UCalendar *cal, UCalendarDaysOfWeek dayOfWeek, UErrorCode* status);
+
+/**
+ * Returns the time during the day at which the weekend begins or ends in
+ * this calendar system.  If ucal_getDayOfWeekType() returns UCAL_WEEKEND_ONSET
+ * for the specified dayOfWeek, return the time at which the weekend begins.
+ * If ucal_getDayOfWeekType() returns UCAL_WEEKEND_CEASE for the specified dayOfWeek,
+ * return the time at which the weekend ends. If ucal_getDayOfWeekType() returns
+ * some other UCalendarWeekdayType for the specified dayOfWeek, is it an error condition
+ * (U_ILLEGAL_ARGUMENT_ERROR).
+ * @param cal The UCalendar to query.
+ * @param dayOfWeek The day of the week for which the weekend transition time is
+ * desired (UCAL_SUNDAY..UCAL_SATURDAY).
+ * @param status The error code for the operation.
+ * @return The milliseconds after midnight at which the weekend begins or ends.
+ * @stable ICU 4.4
+ */
+U_STABLE int32_t U_EXPORT2
+ucal_getWeekendTransition(const UCalendar *cal, UCalendarDaysOfWeek dayOfWeek, UErrorCode *status);
+
+/**
+ * Returns TRUE if the given UDate is in the weekend in
+ * this calendar system.
+ * @param cal The UCalendar to query.
+ * @param date The UDate in question.
+ * @param status The error code for the operation.
+ * @return TRUE if the given UDate is in the weekend in
+ * this calendar system, FALSE otherwise.
+ * @stable ICU 4.4
+ */
+U_STABLE UBool U_EXPORT2
+ucal_isWeekend(const UCalendar *cal, UDate date, UErrorCode *status);
+
+/**
+ * Return the difference between the target time and the time this calendar object is currently set to.
+ * If the target time is after the current calendar setting, the the returned value will be positive.
+ * The field parameter specifies the units of the return value. For example, if field is UCAL_MONTH
+ * and ucal_getFieldDifference returns 3, then the target time is 3 to less than 4 months after the
+ * current calendar setting.
+ *
+ * As a side effect of this call, this calendar is advanced toward target by the given amount. That is,
+ * calling this function has the side effect of calling ucal_add on this calendar with the specified
+ * field and an amount equal to the return value from this function.
+ *
+ * A typical way of using this function is to call it first with the largest field of interest, then
+ * with progressively smaller fields.
+ * 
+ * @param cal The UCalendar to compare and update.
+ * @param target The target date to compare to the current calendar setting.
+ * @param field The field to compare; one of UCAL_ERA, UCAL_YEAR, UCAL_MONTH,
+ * UCAL_WEEK_OF_YEAR, UCAL_WEEK_OF_MONTH, UCAL_DATE, UCAL_DAY_OF_YEAR, UCAL_DAY_OF_WEEK,
+ * UCAL_DAY_OF_WEEK_IN_MONTH, UCAL_AM_PM, UCAL_HOUR, UCAL_HOUR_OF_DAY, UCAL_MINUTE, UCAL_SECOND,
+ * UCAL_MILLISECOND, UCAL_ZONE_OFFSET, UCAL_DST_OFFSET.
+ * @param status A pointer to an UErrorCode to receive any errors
+ * @return The date difference for the specified field.
+ * @stable ICU 4.8
+ */
+U_STABLE int32_t U_EXPORT2 
+ucal_getFieldDifference(UCalendar* cal,
+                        UDate target,
+                        UCalendarDateFields field,
+                        UErrorCode* status);
+
+/**
+ * Time zone transition types for ucal_getTimeZoneTransitionDate
+ * @stable ICU 50
+ */
+enum UTimeZoneTransitionType {
+    /**
+     * Get the next transition after the current date,
+     * i.e. excludes the current date
+     * @stable ICU 50
+     */
+    UCAL_TZ_TRANSITION_NEXT,
+    /**
+     * Get the next transition on or after the current date,
+     * i.e. may include the current date
+     * @stable ICU 50
+     */
+    UCAL_TZ_TRANSITION_NEXT_INCLUSIVE,
+    /**
+     * Get the previous transition before the current date,
+     * i.e. excludes the current date
+     * @stable ICU 50
+     */
+    UCAL_TZ_TRANSITION_PREVIOUS,
+    /**
+     * Get the previous transition on or before the current date,
+     * i.e. may include the current date
+     * @stable ICU 50
+     */
+    UCAL_TZ_TRANSITION_PREVIOUS_INCLUSIVE
+};
+
+typedef enum UTimeZoneTransitionType UTimeZoneTransitionType; /**< @stable ICU 50 */
+
+/**
+* Get the UDate for the next/previous time zone transition relative to
+* the calendar's current date, in the time zone to which the calendar
+* is currently set. If there is no known time zone transition of the
+* requested type relative to the calendar's date, the function returns
+* FALSE.
+* @param cal The UCalendar to query.
+* @param type The type of transition desired.
+* @param transition A pointer to a UDate to be set to the transition time.
+*         If the function returns FALSE, the value set is unspecified.
+* @param status A pointer to a UErrorCode to receive any errors.
+* @return TRUE if a valid transition time is set in *transition, FALSE
+*         otherwise.
+* @stable ICU 50
+*/
+U_STABLE UBool U_EXPORT2 
+ucal_getTimeZoneTransitionDate(const UCalendar* cal, UTimeZoneTransitionType type,
+                               UDate* transition, UErrorCode* status);
+
+/**
+* Converts a system time zone ID to an equivalent Windows time zone ID. For example,
+* Windows time zone ID "Pacific Standard Time" is returned for input "America/Los_Angeles".
+*
+* <p>There are system time zones that cannot be mapped to Windows zones. When the input
+* system time zone ID is unknown or unmappable to a Windows time zone, then this
+* function returns 0 as the result length, but the operation itself remains successful
+* (no error status set on return).
+*
+* <p>This implementation utilizes <a href="http://unicode.org/cldr/charts/supplemental/zone_tzid.html">
+* Zone-Tzid mapping data</a>. The mapping data is updated time to time. To get the latest changes,
+* please read the ICU user guide section <a href="http://userguide.icu-project.org/datetime/timezone#TOC-Updating-the-Time-Zone-Data">
+* Updating the Time Zone Data</a>.
+*
+* @param id            A system time zone ID.
+* @param len           The length of <code>id</code>, or -1 if null-terminated.
+* @param winid         A buffer to receive a Windows time zone ID.
+* @param winidCapacity The capacity of the result buffer <code>winid</code>.
+* @param status        Receives the status.
+* @return              The result string length, not including the terminating null.
+* @see ucal_getTimeZoneIDForWindowsID
+*
+* @stable ICU 52
+*/
+U_STABLE int32_t U_EXPORT2
+ucal_getWindowsTimeZoneID(const UChar* id, int32_t len,
+                            UChar* winid, int32_t winidCapacity, UErrorCode* status);
+
+/**
+* Converts a Windows time zone ID to an equivalent system time zone ID
+* for a region. For example, system time zone ID "America/Los_Angeles" is returned
+* for input Windows ID "Pacific Standard Time" and region "US" (or <code>null</code>),
+* "America/Vancouver" is returned for the same Windows ID "Pacific Standard Time" and
+* region "CA".
+*
+* <p>Not all Windows time zones can be mapped to system time zones. When the input
+* Windows time zone ID is unknown or unmappable to a system time zone, then this
+* function returns 0 as the result length, but the operation itself remains successful
+* (no error status set on return).
+*
+* <p>This implementation utilizes <a href="http://unicode.org/cldr/charts/supplemental/zone_tzid.html">
+* Zone-Tzid mapping data</a>. The mapping data is updated time to time. To get the latest changes,
+* please read the ICU user guide section <a href="http://userguide.icu-project.org/datetime/timezone#TOC-Updating-the-Time-Zone-Data">
+* Updating the Time Zone Data</a>.
+*
+* @param winid         A Windows time zone ID.
+* @param len           The length of <code>winid</code>, or -1 if null-terminated.
+* @param region        A null-terminated region code, or <code>NULL</code> if no regional preference.
+* @param id            A buffer to receive a system time zone ID.
+* @param idCapacity    The capacity of the result buffer <code>id</code>.
+* @param status        Receives the status.
+* @return              The result string length, not including the terminating null.
+* @see ucal_getWindowsTimeZoneID
+*
+* @stable ICU 52
+*/
+U_STABLE int32_t U_EXPORT2
+ucal_getTimeZoneIDForWindowsID(const UChar* winid, int32_t len, const char* region,
+                                UChar* id, int32_t idCapacity, UErrorCode* status);
+
+#endif /* #if !UCONFIG_NO_FORMATTING */
+
+#endif