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.
Time Machine
Intended to be the last version to support macOS 10.12 to 12, and backing up to HFS+ volumes, this contains small improvements particularly for Monterey.
Lists the Standard Exclusions set by the system, explains custom ‘sticky’ exclusions, how iCloud Drive is handled, and oddities with Photos libraries.
Bridging the gap between Undo and backup, its a major productivity feature implemented using a hidden folder at the top level of each volume.
Don’t clutter your backups with files you’d never want to restore. Here are five methods to exclude items from Time Machine backups to keep them leaner.
A great advance in APFS which enables Big Sur’s Sealed System Volume, and backups being made to APFS. Here they’re fully explained.
A lot of what Time Machine does when making backups to an APFS volume remains a mystery. So far we don’t understand the magic used by Apple.
macOS 11.5 will be available in a few days. Should you risk upgrading? Here are some of the major issues which you need to consider when deciding and planning any upgrade.
Most hard disks become increasingly likely to fail after 3 years. All Time Capsules are now in that zone, and should either be replaced or have their hard disks replaced.
Content Caching server originated in 2005, as a feature in Mac OS X Server, which sold Xserves. Time Machine came in 2007, to support Time Capsules. Those legacies are so different, though.
The Eclectic Light Company 