from django.db import models class Event(models.Model): dt = models.DateTimeField() class MaybeEvent(models.Model): dt = models.DateTimeField(blank=True, null=True) class Session(models.Model): name = models.CharField(max_length=20) class SessionEvent(models.Model): dt = models.DateTimeField() session = models.ForeignKey(Session, models.CASCADE, related_name='events') class Timestamp(models.Model): created = models.DateTimeField(auto_now_add=True) updated = models.DateTimeField(auto_now=True) class AllDayEvent(models.Model): day = models.DateField() class DailyEvent(models.Model): time = models.TimeField()