class schedule(object):

    def is_due(self, last_run_at):
        """Returns tuple of two items `(is_due, next_time_to_run)`,
        where next time to run is in seconds.
        e.g.
        * `(True, 20)`, means the task should be run now, and the next
            time to run is in 20 seconds.
        * `(False, 12)`, means the task should be run in 12 seconds.
        You can override this to decide the interval at runtime,
        but keep in mind the value of :setting:`CELERYBEAT_MAX_LOOP_INTERVAL`,
        which decides the maximum number of seconds celerybeat can sleep
        between re-checking the periodic task intervals.  So if you
        dynamically change the next run at value, and the max interval is
        set to 5 minutes, it will take 5 minutes for the change to take
        effect, so you may consider lowering the value of
        :setting:`CELERYBEAT_MAX_LOOP_INTERVAL` if responsiveness is of
        importance to you.
        .. admonition:: Scheduler max interval variance
        The default max loop interval may vary for different schedulers.
        For the default scheduler the value is 5 minutes, but for e.g.
        the django-celery database scheduler the value is 5 seconds.
        """
last_run_at = self.maybe_make_aware(last_run_at)
rem_delta = self.remaining_estimate(last_run_at)
Dynamically Changing Celery Beat Settings