• Dropped support for Python 3.6 and 3.7
• Added support for ZoneInfo time zones and deprecated support for pytz time zones
• Added CalendarIntervalTrigger, backported from the 4.x series
• Added the ability to export and import jobs via scheduler.export_jobs() and scheduler.import_jobs(), respectively
• Removed the dependency on six
• Changed ProcessPoolExecutor to spawn new subprocesses from scratch instead of forking on all platform
• Fixed AsyncIOScheduler inadvertently creating a defunct event loop at start, leading to the scheduler not working at all
• Fixed ProcessPoolExecutor not respecting the passed keyword arguments when a broken pool was being replaced