Since 2005, macOS has had the master launcher launchd and its LaunchAgents and LaunchDaemons. Then in 2014 Apple added Duet Activity Scheduler to run tasks when conditions are suitable.
cron
periodic has been removed from Sequoia. AI doesn’t appear to activate in macOS 15.1 VMs, and they may get a surprise update intended for M4 Macs.
How macOS schedules tasks like making automatic Time Machine backups, from property list to transactions between DAS and CTS.
The story of how Mac OS X went from cron, to launchd, and ended up with Duet Activity Scheduler, to schedule background activities like backups.
How to set your Mac to run scripts, apps and other software automatically, and at regular intervals, using launchd and a property list.
Prior to 10.4, Mac OS X used cron, then scheduling became part of the job of launchd. Later Apple added a new subsystem, Duet Activity Scheduler, which continues to evolve.
What does it take for an app to have ‘activities’ managed for efficiency by CTS? Not a lot – but in return, the management is a black box.
In the first article in this series, I explained how a great many background activities in macOS, including […]
Rather than using cron or launchd, many background services in macOS are now run using Centralized Task Scheduling (CTS). This is how it works.
Scheduling background activities like making backups has moved from cron to launchd, and now to a more complex system. This has reduced the reliability of macOS and made it harder to support.
The Eclectic Light Company 