How to make an unaware datetime timezone aware in python
In general, to make a naive datetime timezone-aware, use the localize method:
import datetime
import pytz
unaware = datetime.datetime(2011, 8, 15, 8, 15, 12, 0)
aware = datetime.datetime(2011, 8, 15, 8, 15, 12, 0, pytz.UTC)
now_aware = pytz.utc.localize(unaware)
assert aware == now_aware
For the UTC timezone, it is not really necessary to use localize
since there is no daylight savings time calculation to handle:
now_aware = unaware.replace(tzinfo=pytz.UTC)
works. (.replace
returns a new datetime; it does not modify unaware
.)
All of these examples use an external module, but you can achieve the same result using just the datetime module, as also presented in this SO answer:
from datetime import datetime
from datetime import timezone
dt = datetime.now()
dt.replace(tzinfo=timezone.utc)
print(dt.replace(tzinfo=timezone.utc).isoformat())
'2017-01-12T22:11:31+00:00'
Fewer dependencies and no pytz issues.
NOTE: If you wish to use this with python3 and python2, you can use this as well for the timezone import (hardcoded for UTC):
try:
from datetime import timezone
utc = timezone.utc
except ImportError:
#Hi there python2 user
class UTC(tzinfo):
def utcoffset(self, dt):
return timedelta(0)
def tzname(self, dt):
return "UTC"
def dst(self, dt):
return timedelta(0)
utc = UTC()
I wrote this at Nov 22 2011 , is Pyhton 2 only , never checked if it work on Python 3
I had use from dt_aware to dt_unaware
dt_unaware = dt_aware.replace(tzinfo=None)
and dt_unware to dt_aware
from pytz import timezone
localtz = timezone('Europe/Lisbon')
dt_aware = localtz.localize(dt_unware)
but answer before is also a good solution.