from zoneinfo import ZoneInfo
from datetime import datetime, timedelta

# same autumn transition, same UTC offsets
OSL = ZoneInfo("Europe/Oslo")
BER = ZoneInfo("Europe/Berlin")

# same point in time
osl_f0 = datetime(2020, 10, 25, 2, 30, fold=0, tzinfo=OSL)
ber_f0 = datetime(2020, 10, 25, 2, 30, fold=0, tzinfo=BER)
assert osl_f0 - ber_f0 == timedelta(0)

# same point in time, one hour later
osl_f1 = datetime(2020, 10, 25, 2, 31, fold=1, tzinfo=OSL)
ber_f1 = datetime(2020, 10, 25, 2, 31, fold=1, tzinfo=BER)
assert osl_f1 - ber_f1 == timedelta(0)

print('All these should be 1:01:00 apart')
print(osl_f1 - osl_f0,'Oslo_1   - Oslo_0')
print(ber_f1 - osl_f0,'Berlin_1 - Oslo_0')
print(osl_f1 - ber_f0,'Oslo_1   - Berlin_0')
print(ber_f1 - ber_f0,'Berlin_1 - Berlin_0')