Days Until Filter in Django

days_until.py

# Inspiration from https://djangosnippets.org/snippets/116/

from django import template
import datetime

register = template.Library()


def days_until(value):
    """ 
    Returns number of days between value and today

    Example usage in template: 
    {% load days_until %}
    {{ ending_time|daysuntil }}
    """
    today = datetime.date.today()
    try:
        diff = value - today
    except TypeError:
        # convert datetime.datetime to datetime.date
        diff = value.date() - today

    if diff.days > 1:
        return '{days}d'.format(days=diff.days)
    elif diff.days == 0:
        return 'expires today'
    else:
        # Date is in the past; return expired message
        return 'expired'

register.filter('daysuntil', days_until)