chrono/chrono/utils/timezone.py

67 lines
2.0 KiB
Python

# chrono - agendas system
# Copyright (C) 2023 Entr'ouvert
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import datetime
import functools
import zoneinfo
import django.utils.timezone
from django.conf import settings
utc = zoneinfo.ZoneInfo('UTC')
@functools.lru_cache()
def get_default_timezone():
"""
Return the default time zone as a tzinfo instance.
This is the time zone defined by settings.TIME_ZONE.
"""
return zoneinfo.ZoneInfo(settings.TIME_ZONE)
def localtime(value=None, timezone=None):
if timezone is None:
timezone = get_default_timezone()
return django.utils.timezone.localtime(value=value, timezone=timezone)
is_aware = django.utils.timezone.is_aware
def make_aware(value, timezone=None, is_dst=None):
if timezone is None:
timezone = get_default_timezone()
return django.utils.timezone.make_aware(value, timezone=timezone, is_dst=is_dst)
def make_naive(value, timezone=None):
if timezone is None:
timezone = get_default_timezone()
return django.utils.timezone.make_naive(value, timezone=timezone)
def now():
"""
Return an aware or naive datetime.datetime, depending on settings.USE_TZ.
"""
if settings.USE_TZ:
# timeit shows that datetime.now(tz=utc) is 24% slower
return datetime.datetime.utcnow().replace(tzinfo=utc)
else:
return datetime.datetime.now()