creating timezone-aware datetime objects

creating time-aware-datetime-object.py

from django.utils import timezone
import pytz

pytz_tz = pytz.timezone('America/Chicago')

# wrong -- The direct approach leads to somewhat random time offsets between timezones.
adt = timezone.datetime(year=2016, month=1, day=6, tzinfo=pytz_tz)

# correct: Localize a naive datetime.
ndt = timezone.datetime(year=2016, month=1, day=6)
adt = pytz_tz.localize(ndt)

# Bonus: once your datetime is aware, you can easily change timezones.
denver_tz = pytz.timezone('America/Denver')
denver_adt = adt.astimezone(denver_tz)

# Summary: You want an aware datetime in your timezone of choice, pytz_tz.
# If you have a naive datetime, use localize, a method on pytz timezone obects:
adt = pytz_tz.localize(ndt)
# If you have an aware datetime, use astimezone, a method on aware datetime obects.
adt = adt.astimezone(pytz_tz)