djavedt 1.0.0

Some useful datetime functions for Django

Introduction

These utility functions are helpful in handling dates, datetimes, and timezones in Django.

Examples

Let's say you have the following in your Django settings.py

TIME_ZONE = 'EST'
USE_TZ = True

Now let's attempt to write our own tomorrow() function.

from datetime import timedelta
from django.utils.timezone import now

def tomorrow():
  # Subtle bug! Django's now() function returns a timezone enabled datetime
  # in UTC, regardless of the TIME_ZONE setting. If it's 11 Wednesday
  # MORNING in New York, this function will work. But if it's 11 Wednesday
  # NIGHT in New York, the UTC timezone is already in Thursday, so in that
  # case this code will return Friday.
  return now().date() + timedelta(days=1)

Here's one way to fix the problem.

from datetime import timedelta
from djavedt import now

def tomorrow():
  # djavedt's now() function returns a timezone enabled datetime in the
  # timezone of the TIME_ZONE setting, which is EST in our example. So this
  # function will work as expected at 11PM in New York.
  return now().date() + timedelta(days=1)