django1/django/utils/tzinfo.py

70 lines
2.0 KiB
Python
Raw Normal View History

"Implementation of tzinfo classes for use with datetime.datetime."
import locale
import time
from datetime import timedelta, tzinfo
from django.utils.encoding import smart_unicode
try:
DEFAULT_ENCODING = locale.getdefaultlocale()[1] or 'ascii'
except:
# Any problems at all determining the locale and we fallback. See #5846.
DEFAULT_ENCODING = 'ascii'
class FixedOffset(tzinfo):
"Fixed offset in minutes east from UTC."
def __init__(self, offset):
self.__offset = timedelta(minutes=offset)
self.__name = u"%+03d%02d" % (offset // 60, offset % 60)
def __repr__(self):
return self.__name
def utcoffset(self, dt):
return self.__offset
def tzname(self, dt):
return self.__name
def dst(self, dt):
return timedelta(0)
class LocalTimezone(tzinfo):
"Proxy timezone information from time module."
def __init__(self, dt):
tzinfo.__init__(self, dt)
self._tzname = self.tzname(dt)
def __repr__(self):
return self._tzname
def utcoffset(self, dt):
if self._isdst(dt):
return timedelta(seconds=-time.altzone)
else:
return timedelta(seconds=-time.timezone)
def dst(self, dt):
if self._isdst(dt):
return timedelta(seconds=-time.altzone) - timedelta(seconds=-time.timezone)
else:
return timedelta(0)
def tzname(self, dt):
try:
return smart_unicode(time.tzname[self._isdst(dt)], DEFAULT_ENCODING)
except UnicodeDecodeError:
return None
def _isdst(self, dt):
tt = (dt.year, dt.month, dt.day, dt.hour, dt.minute, dt.second, dt.weekday(), 0, -1)
try:
stamp = time.mktime(tt)
except OverflowError:
# 32 bit systems can't handle dates after Jan 2038, so we fake it
# in that case (since we only care about the DST flag here).
tt = (2037,) + tt[1:]
stamp = time.mktime(tt)
tt = time.localtime(stamp)
return tt.tm_isdst > 0