templatetag.py

from django import template


register = template.Library()


@register.simple_tag
def date_range(start, end):
    """ Takes a start date, and end date, then formats them as a range. """
    if end - start >= 365:  # More than a year
        formats = ('%B %d, %Y', '%B %d, %Y')
    elif end.month != start.month:  # Same year, different months
        formats = ('%B %d', '%B %d, %Y')
    else:  # Same month and year
        formats = ('%B %d', '%d, %Y')

    return start.strftime(formats[0]), '-', end.strftime(formats[1])