Tag Archives: pytz

Convert UTC time to local in Python

UTC to local:

EPOCH_DATETIME = datetime.datetime(1970,1,1)
SECONDS_PER_DAY = 24*60*60

def utc_to_local_datetime( utc_datetime ):
    delta = utc_datetime - EPOCH_DATETIME
    utc_epoch = SECONDS_PER_DAY * delta.days + delta.seconds
    time_struct = time.localtime( utc_epoch )
    dt_args = time_struct[:6] + (delta.microseconds,)
    return datetime.datetime( *dt_args )

UTC to local:

>>> import datetime, pytz
>>> local_tz = pytz.timezone('Asia/Tokyo')
>>> datetime.datetime.now().replace(tzinfo=pytz.utc).astimezone(local_tz)
datetime.datetime(2011, 3, 4, 16, 2, 3, 311670, tzinfo=<DstTzInfo 'Asia/Tokyo' JST+9:00:00 STD>)

local to UTC:

>>> import datetime, pytz
>>> datetime.datetime.now()
datetime.datetime(2011, 3, 4, 15, 6, 6, 446583)
>>> datetime.datetime.now(pytz.utc)
datetime.datetime(2011, 3, 4, 7, 6, 22, 198472, tzinfo=<UTC>)

References
https://k4ml.wordpress.com/2011/03/04/convert-utc-time-to-local/
https://stackoverflow.com/questions/4563272/convert-a-python-utc-datetime-to-a-local-datetime-using-only-python-standard-lib