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annotate CSP2/CSP2_env/env-d9b9114564458d9d-741b3de822f2aaca6c6caa4325c4afce/lib/python3.8/site-packages/pytz/reference.py @ 68:5028fdace37b

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planemo upload commit 2e9511a184a1ca667c7be0c6321a36dc4e3d116d
author jpayne
date Tue, 18 Mar 2025 16:23:26 -0400
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jpayne@68 1 '''
jpayne@68 2 Reference tzinfo implementations from the Python docs.
jpayne@68 3 Used for testing against as they are only correct for the years
jpayne@68 4 1987 to 2006. Do not use these for real code.
jpayne@68 5 '''
jpayne@68 6
jpayne@68 7 from datetime import tzinfo, timedelta, datetime
jpayne@68 8 from pytz import HOUR, ZERO, UTC
jpayne@68 9
jpayne@68 10 __all__ = [
jpayne@68 11 'FixedOffset',
jpayne@68 12 'LocalTimezone',
jpayne@68 13 'USTimeZone',
jpayne@68 14 'Eastern',
jpayne@68 15 'Central',
jpayne@68 16 'Mountain',
jpayne@68 17 'Pacific',
jpayne@68 18 'UTC'
jpayne@68 19 ]
jpayne@68 20
jpayne@68 21
jpayne@68 22 # A class building tzinfo objects for fixed-offset time zones.
jpayne@68 23 # Note that FixedOffset(0, "UTC") is a different way to build a
jpayne@68 24 # UTC tzinfo object.
jpayne@68 25 class FixedOffset(tzinfo):
jpayne@68 26 """Fixed offset in minutes east from UTC."""
jpayne@68 27
jpayne@68 28 def __init__(self, offset, name):
jpayne@68 29 self.__offset = timedelta(minutes=offset)
jpayne@68 30 self.__name = name
jpayne@68 31
jpayne@68 32 def utcoffset(self, dt):
jpayne@68 33 return self.__offset
jpayne@68 34
jpayne@68 35 def tzname(self, dt):
jpayne@68 36 return self.__name
jpayne@68 37
jpayne@68 38 def dst(self, dt):
jpayne@68 39 return ZERO
jpayne@68 40
jpayne@68 41
jpayne@68 42 import time as _time
jpayne@68 43
jpayne@68 44 STDOFFSET = timedelta(seconds=-_time.timezone)
jpayne@68 45 if _time.daylight:
jpayne@68 46 DSTOFFSET = timedelta(seconds=-_time.altzone)
jpayne@68 47 else:
jpayne@68 48 DSTOFFSET = STDOFFSET
jpayne@68 49
jpayne@68 50 DSTDIFF = DSTOFFSET - STDOFFSET
jpayne@68 51
jpayne@68 52
jpayne@68 53 # A class capturing the platform's idea of local time.
jpayne@68 54 class LocalTimezone(tzinfo):
jpayne@68 55
jpayne@68 56 def utcoffset(self, dt):
jpayne@68 57 if self._isdst(dt):
jpayne@68 58 return DSTOFFSET
jpayne@68 59 else:
jpayne@68 60 return STDOFFSET
jpayne@68 61
jpayne@68 62 def dst(self, dt):
jpayne@68 63 if self._isdst(dt):
jpayne@68 64 return DSTDIFF
jpayne@68 65 else:
jpayne@68 66 return ZERO
jpayne@68 67
jpayne@68 68 def tzname(self, dt):
jpayne@68 69 return _time.tzname[self._isdst(dt)]
jpayne@68 70
jpayne@68 71 def _isdst(self, dt):
jpayne@68 72 tt = (dt.year, dt.month, dt.day,
jpayne@68 73 dt.hour, dt.minute, dt.second,
jpayne@68 74 dt.weekday(), 0, -1)
jpayne@68 75 stamp = _time.mktime(tt)
jpayne@68 76 tt = _time.localtime(stamp)
jpayne@68 77 return tt.tm_isdst > 0
jpayne@68 78
jpayne@68 79 Local = LocalTimezone()
jpayne@68 80
jpayne@68 81
jpayne@68 82 def first_sunday_on_or_after(dt):
jpayne@68 83 days_to_go = 6 - dt.weekday()
jpayne@68 84 if days_to_go:
jpayne@68 85 dt += timedelta(days_to_go)
jpayne@68 86 return dt
jpayne@68 87
jpayne@68 88
jpayne@68 89 # In the US, DST starts at 2am (standard time) on the first Sunday in April.
jpayne@68 90 DSTSTART = datetime(1, 4, 1, 2)
jpayne@68 91 # and ends at 2am (DST time; 1am standard time) on the last Sunday of Oct.
jpayne@68 92 # which is the first Sunday on or after Oct 25.
jpayne@68 93 DSTEND = datetime(1, 10, 25, 1)
jpayne@68 94
jpayne@68 95
jpayne@68 96 # A complete implementation of current DST rules for major US time zones.
jpayne@68 97 class USTimeZone(tzinfo):
jpayne@68 98
jpayne@68 99 def __init__(self, hours, reprname, stdname, dstname):
jpayne@68 100 self.stdoffset = timedelta(hours=hours)
jpayne@68 101 self.reprname = reprname
jpayne@68 102 self.stdname = stdname
jpayne@68 103 self.dstname = dstname
jpayne@68 104
jpayne@68 105 def __repr__(self):
jpayne@68 106 return self.reprname
jpayne@68 107
jpayne@68 108 def tzname(self, dt):
jpayne@68 109 if self.dst(dt):
jpayne@68 110 return self.dstname
jpayne@68 111 else:
jpayne@68 112 return self.stdname
jpayne@68 113
jpayne@68 114 def utcoffset(self, dt):
jpayne@68 115 return self.stdoffset + self.dst(dt)
jpayne@68 116
jpayne@68 117 def dst(self, dt):
jpayne@68 118 if dt is None or dt.tzinfo is None:
jpayne@68 119 # An exception may be sensible here, in one or both cases.
jpayne@68 120 # It depends on how you want to treat them. The default
jpayne@68 121 # fromutc() implementation (called by the default astimezone()
jpayne@68 122 # implementation) passes a datetime with dt.tzinfo is self.
jpayne@68 123 return ZERO
jpayne@68 124 assert dt.tzinfo is self
jpayne@68 125
jpayne@68 126 # Find first Sunday in April & the last in October.
jpayne@68 127 start = first_sunday_on_or_after(DSTSTART.replace(year=dt.year))
jpayne@68 128 end = first_sunday_on_or_after(DSTEND.replace(year=dt.year))
jpayne@68 129
jpayne@68 130 # Can't compare naive to aware objects, so strip the timezone from
jpayne@68 131 # dt first.
jpayne@68 132 if start <= dt.replace(tzinfo=None) < end:
jpayne@68 133 return HOUR
jpayne@68 134 else:
jpayne@68 135 return ZERO
jpayne@68 136
jpayne@68 137 Eastern = USTimeZone(-5, "Eastern", "EST", "EDT")
jpayne@68 138 Central = USTimeZone(-6, "Central", "CST", "CDT")
jpayne@68 139 Mountain = USTimeZone(-7, "Mountain", "MST", "MDT")
jpayne@68 140 Pacific = USTimeZone(-8, "Pacific", "PST", "PDT")