Migrating from previous versions of APScheduler

From v3.0 to v3.2

Prior to v3.1, the scheduler inadvertently exposed the ability to fetch and manipulate jobs before the scheduler had been started. The scheduler now requires you to call scheduler.start() before attempting to access any of the jobs in the job stores. To ensure that no old jobs are mistakenly executed, you can start the scheduler in paused mode (scheduler.start(paused=True)) (introduced in v3.2) to avoid any premature job processing.

From v2.x to v3.0

The 3.0 series is API incompatible with previous releases due to a design overhaul.

Scheduler changes

  • The concept of “standalone mode” is gone. For standalone=True, use BlockingScheduler instead, and for standalone=False, use BackgroundScheduler. BackgroundScheduler matches the old default semantics.

  • Job defaults (like misfire_grace_time and coalesce) must now be passed in a dictionary as the job_defaults option to configure(). When supplying an ini-style configuration as the first argument, they will need a corresponding job_defaults. prefix.

  • The configuration key prefix for job stores was changed from jobstore. to jobstores. to match the dict-style configuration better.

  • The max_runs option has been dropped since the run counter could not be reliably preserved when replacing a job with another one with the same ID. To make up for this, the end_date option was added to cron and interval triggers.

  • The old thread pool is gone, replaced by ThreadPoolExecutor. This means that the old threadpool options are no longer valid. See Configuring the scheduler on how to configure executors.

  • The trigger-specific scheduling methods have been removed entirely from the scheduler. Use the generic add_job() method or the scheduled_job() decorator instead. The signatures of these methods were changed significantly.

  • The shutdown_threadpool and close_jobstores options have been removed from the shutdown() method. Executors and job stores are now always shut down on scheduler shutdown.

  • unschedule_job() and unschedule_func() have been replaced by remove_job(). You can also unschedule a job by using the job handle returned from add_job().

Job store changes

The job store system was completely overhauled for both efficiency and forwards compatibility. Unfortunately, this means that the old data is not compatible with the new job stores. If you need to migrate existing data from APScheduler 2.x to 3.x, contact the APScheduler author.

The Shelve job store had to be dropped because it could not support the new job store design. Use SQLAlchemyJobStore with SQLite instead.

Trigger changes

From 3.0 onwards, triggers now require a pytz timezone. This is normally provided by the scheduler, but if you were instantiating triggers manually before, then one must be supplied as the timezone argument.

The only other backwards incompatible change was that get_next_fire_time() takes two arguments now: the previous fire time and the current datetime.


APScheduler 3.9.0 added experimental support for non-pytz timezones.

From v1.x to 2.0

There have been some API changes since the 1.x series. This document explains the changes made to v2.0 that are incompatible with the v1.x API.

API changes

  • The behavior of cron scheduling with regards to default values for omitted fields has been made more intuitive – omitted fields lower than the least significant explicitly defined field will default to their minimum values except for the week number and weekday fields

  • SchedulerShutdownError has been removed – jobs are now added tentatively and scheduled for real when/if the scheduler is restarted

  • Scheduler.is_job_active() has been removed – use job in scheduler.get_jobs() instead

  • dump_jobs() is now print_jobs() and prints directly to the given file or sys.stdout if none is given

  • The repeat parameter was removed from add_interval_job() and interval_schedule() in favor of the universal max_runs option

  • unschedule_func() now raises a KeyError if the given function is not scheduled

  • The semantics of shutdown() have changed – the method no longer accepts a numeric argument, but two booleans

Configuration changes

  • The scheduler can no longer be reconfigured while it’s running