Schedules¶
Schedule classes for periodic tasks (used with celery beat).
crontab¶
crontab ¶
Bases: BaseSchedule
Crontab schedule.
A Crontab can be used as the run_every value of a
periodic task entry to add :manpage:crontab(5)-like scheduling.
Like a :manpage:cron(5)-job, you can specify units of time of when
you'd like the task to execute. It's a reasonably complete
implementation of :command:cron's features, so it should provide a fair
degree of scheduling needs.
You can specify a minute, an hour, a day of the week, a day of the month, and/or a month in the year in any of the following formats:
.. attribute:: minute
- A (list of) integers from 0-59 that represent the minutes of
an hour of when execution should occur; or
- A string representing a Crontab pattern. This may get pretty
advanced, like ``minute='*/15'`` (for every quarter) or
``minute='1,13,30-45,50-59/2'``.
.. attribute:: hour
- A (list of) integers from 0-23 that represent the hours of
a day of when execution should occur; or
- A string representing a Crontab pattern. This may get pretty
advanced, like ``hour='*/3'`` (for every three hours) or
``hour='0,8-17/2'`` (at midnight, and every two hours during
office hours).
.. attribute:: day_of_week
- A (list of) integers from 0-6, where Sunday = 0 and Saturday =
6, that represent the days of a week that execution should
occur.
- A string representing a Crontab pattern. This may get pretty
advanced, like ``day_of_week='mon-fri'`` (for weekdays only).
(Beware that ``day_of_week='*/2'`` does not literally mean
'every two days', but 'every day that is divisible by two'!)
.. attribute:: day_of_month
- A (list of) integers from 1-31 that represents the days of the
month that execution should occur.
- A string representing a Crontab pattern. This may get pretty
advanced, such as ``day_of_month='2-30/2'`` (for every even
numbered day) or ``day_of_month='1-7,15-21'`` (for the first and
third weeks of the month).
.. attribute:: month_of_year
- A (list of) integers from 1-12 that represents the months of
the year during which execution can occur.
- A string representing a Crontab pattern. This may get pretty
advanced, such as ``month_of_year='*/3'`` (for the first month
of every quarter) or ``month_of_year='2-12/2'`` (for every even
numbered month).
.. attribute:: nowfun
Function returning the current date and time
(:class:`~datetime.datetime`).
.. attribute:: app
The Celery app instance.
It's important to realize that any day on which execution should
occur must be represented by entries in all three of the day and
month attributes. For example, if day_of_week is 0 and
day_of_month is every seventh day, only months that begin
on Sunday and are also in the month_of_year attribute will have
execution events. Or, day_of_week is 1 and day_of_month
is '1-7,15-21' means every first and third Monday of every month
present in month_of_year.
__init__ ¶
__init__(
minute: Cronspec = "*",
hour: Cronspec = "*",
day_of_week: Cronspec = "*",
day_of_month: Cronspec = "*",
month_of_year: Cronspec = "*",
**kwargs: Any,
) -> None
is_due ¶
Return tuple of (is_due, next_time_to_run).
If :setting:beat_cron_starting_deadline has been specified, the
scheduler will make sure that the last_run_at time is within the
deadline. This prevents tasks that could have been run according to
the crontab, but didn't, from running again unexpectedly.
Note: Next time to run is in seconds.
SeeAlso:
:meth:celery.schedules.schedule.is_due for more information.
remaining_estimate ¶
Estimate of next run time.
Returns when the periodic task should run next as a
:class:~datetime.timedelta.
schedule¶
schedule ¶
Bases: BaseSchedule
Schedule for periodic task.
Arguments:
run_every (float, ~datetime.timedelta): Time interval.
relative (bool): If set to True the run time will be rounded to the
resolution of the interval.
nowfun (Callable): Function returning the current date and time
(:class:~datetime.datetime).
app (Celery): Celery app instance.
__init__ ¶
__init__(
run_every: float | timedelta | None = None,
relative: bool = False,
nowfun: Callable | None = None,
app: Celery | None = None,
) -> None
is_due ¶
Return tuple of (is_due, next_time_to_check).
Notes: - next time to check is in seconds.
- ``(True, 20)``, means the task should be run now, and the next
time to check is in 20 seconds.
- ``(False, 12.3)``, means the task is not due, but that the
scheduler should check again in 12.3 seconds.
The next time to check is used to save energy/CPU cycles,
it does not need to be accurate but will influence the precision
of your schedule. You must also keep in mind
the value of :setting:beat_max_loop_interval,
that decides the maximum number of seconds the scheduler can
sleep between re-checking the periodic task intervals. So if you
have a task that changes schedule at run-time then your next_run_at
check will decide how long it will take before a change to the
schedule takes effect. The max loop interval takes precedence
over the next check at value returned.
.. 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 example
the :pypi:`django-celery-beat` database scheduler the value
is 5 seconds.
solar¶
solar ¶
Bases: BaseSchedule
Solar event.
A solar event can be used as the run_every value of a
periodic task entry to schedule based on certain solar events.
Notes:
Available event values are:
- ``dawn_astronomical``
- ``dawn_nautical``
- ``dawn_civil``
- ``sunrise``
- ``solar_noon``
- ``sunset``
- ``dusk_civil``
- ``dusk_nautical``
- ``dusk_astronomical``
Arguments:
event (str): Solar event that triggers this task.
See note for available values.
lat (float): The latitude of the observer.
lon (float): The longitude of the observer.
nowfun (Callable): Function returning the current date and time
as a class:~datetime.datetime.
app (Celery): Celery app instance.
is_due ¶
Return tuple of (is_due, next_time_to_run).
Note: next time to run is in seconds.
See Also:
:meth:celery.schedules.schedule.is_due for more information.
remaining_estimate ¶
Return estimate of next time to run.
Returns: ~datetime.timedelta: when the periodic task should run next, or if it shouldn't run today (e.g., the sun does not rise today), returns the time when the next check should take place.