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.
launchd
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.
What’s the quickest way to tear down all user apps and services? Or to force a restart? The answer is in the command tool launchctl.
When you want software to run automatically each time you Mac starts up, there are several ways of doing that. Here’s your choice.
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.
New release lets you save and re-open activity configurations in simple plist files, and fixes a couple of annoying bugs.
Background activities scheduled by third-party software currently use launchd, and run the risk of affecting the user. Would GCD be a better choice of dispatcher?
An experimental tool to let you schedule background tasks of your own, which are managed by Grand Central Dispatch. First alpha release.
The Eclectic Light Company 