save time zone in Django Models

I think the above answers are all correct, but I leave mine here as an simple example…

class UserProfile(models.Model):  

    import pytz
    TIMEZONES = tuple(zip(pytz.all_timezones, pytz.all_timezones))

    # ...
    timezone = models.CharField(max_length=32, choices=TIMEZONES, 
    default="UTC")
# ...