Mac mini Time Machine timeline shows erratic behavior

DoctorBashir wrote:

I have a MacMini running Tahoe 26.7 Recently, I had a need to browse my Time Machine backup. When I first entered the Browse TM Backups I noticed that the timeline was only showing backups tick marks for the current month. Then the timeline jumped and displayed, apparently, all my backups going back at least 2.5 years with the tick marks for the current month not visible. When I tried to access the most recent backup for the current month the only tick mark visible for the month was for 'Now'. When I tried to scroll through the current month backup dates, the whole time line moved up until it jumped back to 2024.

If I step through the backup using the up/down arrows next to the Finder windows all the dates and times appear to be present.

Essentially the timeline is behaving very erratically, and the tick maks for current month are only visible for a short time.

I have cleared the cache and rebuilt the backup index but it didn't help. Does anyone have any idea why the time line is behaving like this and how to fix it?

Sounds like the complex database is corrupt.

I would erase/reformat/initialize that backup drive and start a new backup database.

DiskUtility>View>Show all Devices. You are reformating the Parent drive (top most)

Erase and reformat a storage device in Disk Utility on Mac

Erase and reformat a storage device in Disk Utility on Mac - Apple Support

If you value your user data

3-2-1 Backup Strategy: three copies of your data, two different methods, and one offsite.

More than one device, more than one backup methodology— and backup regularly.

Back up your Mac Back up your Mac with Time Machine - Apple Support

etresoft wrote:

As far as I know, that's how the timeline has always behaved.

+1: Same here. I've found that it sometimes helps to restart the Mac and try again.

DoctorBashir wrote:

I have cleared the cache and rebuilt the backup index but it didn't help. Does anyone have any idea why the time line is behaving like this and how to fix it?

As far as I know, that's how the timeline has always behaved.