Naive and Aware Datetime Deltas

dt.py

from __future__ import print_function

import datetime
import pytz

paris = pytz.timezone('Europe/Paris')
utc = pytz.utc

before_naive = datetime.datetime(2013, 3, 31, 1, 59)
before_paris = paris.localize(before_naive)
before_utc = before_paris.astimezone(utc)

delta = datetime.timedelta(minutes=1)
after_utc = (before_utc + delta)
after_paris = after_utc.astimezone(paris)

# Compute aware deltas
minutes_paris = (after_paris - before_paris).total_seconds() / 60
minutes_utc = (after_utc - before_utc).total_seconds() / 60

# Compute naive deltas
naive_minutes_paris = (after_paris.replace(tzinfo=None) - before_paris.replace(tzinfo=None)).total_seconds() / 60
naive_minutes_utc = (after_utc.replace(tzinfo=None) - before_utc.replace(tzinfo=None)).total_seconds() / 60

print("Paris")
print(before_paris)
print(after_paris)
print("Minutes:", minutes_paris) # 1 minute, as expected
print("Naive Minutes:", naive_minutes_paris) # 61 minutes, as visually seen.
print()
print("UTC")
print(before_utc)
print(after_utc)
print("Minutes:", minutes_utc) # 1 minute, as expected.
print("Naive Minutes:", naive_minutes_utc) # 1 minute, as visually seen.