BaseSchedule

This class serves as the abstract base for all schedule types, providing a common interface for determining when a task is due to run. It manages time-aware calculations, timezone conversions, and estimation logic for the next scheduled execution. Subclasses are expected to implement the core scheduling logic by overriding the is_due and remaining_estimate methods.

Attributes

Attribute	Type	Description
nowfun	`Callable	None`
_app	`Celery	None`
app	[Celery](../app/base/celery.md?sid=celery_app_base_celery)	The Celery application instance, which defaults to the current active application if not explicitly provided.
tz	tzinfo	The timezone information retrieved from the associated Celery application's configuration.
utc_enabled	bool	A boolean flag indicating whether UTC is enabled in the Celery application configuration.

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Constructor

Signature

def BaseSchedule(
    nowfun: Callable | None = None,
    app: Celery | None = None
) - > null

Parameters

Name	Type	Description
nowfun	`Callable	None` = None
app	`Celery	None` = None

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Signature

def BaseSchedule(
    nowfun: Callable | None = None,
    app: Celery | None = None
) - > null

Parameters

Name	Type	Description
nowfun	`Callable	None` = None
app	`Celery	None` = None

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Methods

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now()

@classmethod
def now() - > datetime

Returns the current datetime using either the custom time source or the application's default clock.

Returns

Type	Description
datetime	The current datetime object representing 'now'.

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remaining_estimate()

@classmethod
def remaining_estimate(
    last_run_at: datetime
) - > timedelta

Calculates the time remaining until the next scheduled execution occurs.

Parameters

Name	Type	Description
last_run_at	datetime	The timestamp of the most recent successful execution.

Returns

Type	Description
timedelta	The duration of time until the next run is due.

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is_due()

@classmethod
def is_due(
    last_run_at: datetime
) - > tuple[bool, datetime]

Determines if the schedule is ready for execution based on the last run time.

Parameters

Name	Type	Description
last_run_at	datetime	The timestamp of the most recent successful execution.

Returns

Type	Description
tuple[bool, datetime]	A tuple containing a boolean indicating if it is due and the number of seconds to wait until the next check.

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maybe_make_aware()

@classmethod
def maybe_make_aware(
    dt: datetime,
    naive_as_utc: bool = True
) - > datetime

Ensures a datetime object is timezone-aware using the schedule's configured timezone.

Parameters

Name	Type	Description
dt	datetime	The datetime object to be converted or localized.
naive_as_utc	bool = True	If True, treats naive datetime objects as UTC before conversion.

Returns

Type	Description
datetime	A timezone-aware datetime object.

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app()

@classmethod
def app() - > [Celery](../app/base/celery.md?sid=celery_app_base_celery)

Retrieves the Celery application instance associated with this schedule, falling back to the current global app if none is set.

Returns

Type	Description
[Celery](../app/base/celery.md?sid=celery_app_base_celery)	The active Celery application instance.

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tz()

@classmethod
def tz() - > tzinfo

Retrieves the timezone information from the associated Celery application.

Returns

Type	Description
tzinfo	The timezone object used for scheduling calculations.

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utc_enabled()

@classmethod
def utc_enabled() - > bool

Checks the application configuration to determine if UTC mode is active.

Returns

Type	Description
bool	True if UTC is enabled in the application configuration, False otherwise.

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to_local()

@classmethod
def to_local(
    dt: datetime
) - > datetime

Converts a datetime object to local time if UTC is not enabled in the application configuration.

Parameters

Name	Type	Description
dt	datetime	The datetime object to potentially localize.

Returns

Type	Description
datetime	The localized datetime object or the original datetime if UTC is enabled.

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