HFS and the Date & Time control panel from Mac OS 9.x can manage dates up to February 6, 2040 at 06:28:15, after which the clock defined by its epoch will cycle back to January 1904. Apple has since been migrating modern macOS users to its APFS file system, which does not have this limitation.
- 2020 date limit, a date-related software bug in Mac OS 8.6.1 and earlier.
- 2038 date limit, an old Unix-based limitation of Mac OS X versions before 10.6.
- 2554 date limit, a timestamp limit in the Apple File System.