datetime_timezone_exaples.py

import datetime
import pytz

# http://pytz.sourceforge.net/

# HINT: Do not use tzinfo on datetimes or pelace on datetimes because the pytz lib will randomly choose 
#       a daylight saving time offset. For vienne this would be in most cases 5 minutes off :(
#       Instead us .localize() and .astimezone()

# Create timezone object with Europe/Vienna as the timzone (the timzone that your naive datetime is really ment for)
vtz = pytz.timezone("Europe/Vienna")

# Just a naive datetime with no furhter timzone or daylight saving time info
yearend_naive = datetime.datetime(r.meldungs_jahr, 12, 31, 23, 59, 59, 999)

# Now we convert the datetime object to a timezone object with the correct timezone and daylight saving time information
yearend_vtz = vtz.localize(yearend_naive, is_dst=True)

# Create an other timzone object with the desired timzone - in this example UTC e.g.: to store it in odoo fields ;)
yearend_utc = yearend_vtz.astimezone(pytz.UTC)