Time Machine local snapshots are NOT hourly in macOS Sequoia 15.5 — only two are kept, and only once daily? [Detailed observations]

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Time Machine local snapshots are NOT hourly in macOS Sequoia 15.5 — only two are kept, and only once daily? [Detailed observations]

Hi everyone,

I’ve been closely monitoring Time Machine on my new MacBook Pro (2024) running macOS Sequoia 15.5, and I’ve discovered a strange deviation from Apple’s official behavior for local APFS snapshots.

According to Apple documentation, Time Machine is supposed to:

Create hourly local snapshots if the backup drive is not connected.
Retain daily local snapshots for 30 days, assuming there’s space.

However, that’s not what I’m seeing.

My Setup:

MacBook Pro (M4 Pro) — macOS Sequoia 15.5
External Backup Drive: 2TB HDD via USB, formatted as APFS (Encrypted)
Daily external backups are working flawlessly.

Time Machine Log from June 5–9:

2:14A (6-5-25) - external hard drive

3:34A (6-5-25) - local

4:10A (6-6-25) - local

4:46A (6-6-25) - external hard drive

2:11A (6-7-25) - local

2:54A (6-7-25) - external hard drive

5:33A (6-8-25) - local

5:52A (6-8-25) - external hard drive

9:44A (6-9-25) - local

9:51A (6-9-25) - external hard drive

Confirmed Behavior:

Only one local snapshot per day, always within ~60 mins of the external backup.
Only two (2) local snapshots are ever retained.
Terminal shows this clearly (tmutil listlocalsnapshots /):

zshCopyEditcom.apple.TimeMachine.2025-06-08-053306.local  
com.apple.TimeMachine.2025-06-09-094455.local

Older snapshots (from 6/5, 6/6, etc.) are gone.
Time Machine app (when choosing browse backups) shows no visual difference between local vs. external snapshots, but timestamps match this data exactly.

Anyone else seeing this?

Anybody have any idea what the heck is going on here and if this is a bug or standard behavior? If it's supposed to behave like this, why does Apple's manuals state differently?

Thanks in advance for any insights!

MacBook Pro 14″, macOS 15.5

Posted on Jun 10, 2025 7:51 AM

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Answer 1

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Link007 Author

Level 1

9 points

Jun 12, 2025 9:30 AM in response to leroydouglas

Just to close the book on this - I tested this by switching to "Automatic Hourly" - and both local snapshots and external disk occur hourly (or just local if backup disk is not mounted).

My confusion was Apple claiming that HOURLY Local Snapshots are the default, regardless of what your backup disk is doing. This is no longer the case (although my research tells me it once was true). For Sequoia, Local Snapshots follow the lead of your settings for your backup disk (hourly, daily, or weekly).

Even Apple Support personnel seemingly hasn't figured this out yet....

As is common knowledge, Local Snapshots typically are deleted after 24 hours.

One final note - my testing shows that the Local Snapshots will continue even if the backup disk is not mounted. However, it will still follow the settings (hourly, daily, or weekly) set by the backup disk.

Thanks for everyone's help in figuring this out.

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Answer 2

Link007 Author

Level 1

9 points

Jun 22, 2025 9:32 PM in response to VSona

Ah this is fascinating. Thanks for your reply. I am also on macOS 15.5, and APFS-format backup drive. However it's an M4 Pro Chip.

I was able to get local snapshots to happen hourly, but only when also setting my Time Machine to Automatic(Hourly). As soon as I swapped it back to Automatic(Daily), the local snapshots follow suit.

It seems my only route right now is to bring it up with Apple. Is there any kind of secret to talking to someone at Apple Support who actually knows something? In my experience the support folks have never been any help. Maybe I should try Genius Bar?

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Answer 3

Barney-15E

Level 10

123,472 points

Jun 11, 2025 1:38 PM in response to Link007

Local snapshots only exist to back up if a regular backup doesn’t complete. If your drive is connected and it’s backing up, any local snapshots made since the last daily backup will be merged into that daily backup and removed.

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Answer 4

VSona

Level 1

12 points

Jun 22, 2025 6:14 AM in response to Link007

This should be unexpected behavior.

I use Time Machine and set to Automatic(Daily). These local snapshots are:

Hourly snapshots retained within 24 hours. That said, my Mac makes hourly local snapshots even though external backups are daily, and the system deletes old ones.
The last local snapshot generated on backup. This is supposed to accelerate the next backup process.

My list of local snapshots tends to be long anytime I see it. You may need to test in a fresh environment or feedback to or ask Apple.

My environment: macOS 15.5, APFS-format backup drive, M4 chip.

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Answer 5

leroydouglas

Level 10

201,980 points

Jun 10, 2025 8:03 AM in response to Link007

Link007 wrote:

Hi everyone,

I’ve been closely monitoring Time Machine on my new MacBook Pro (2024) running macOS Sequoia 15.5, and I’ve discovered a strange deviation from Apple’s official behavior for local APFS snapshots.

Thanks in advance for any insights!

You can try a Safeboot to sort anomalies...Start up your Mac in safe mode - Apple Support

Make changes to your Time Machine Settings...

for your external—

on a HDD you can try HFS+

On a SSD you should be APFS

Erase and reformat a storage device in Disk Utility on Mac— and start a fresh

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

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Answer 6

Jun 10, 2025 9:14 AM in response to Link007

It seems you have TM configured for daily backups, not hourly backups. This is exactly the behavior for once a day daily backups (although you may see up to three snapshots for a while since TM may make a fresh snapshot if it has been a while since the backup drive has been connected).

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Answer 7

Link007 Author

Level 1

9 points

Jun 10, 2025 9:50 AM in response to HWTech

Thanks so much for your reply. I do indeed have TM configured for daily backups. But that doesn't explain why the local snapshots are being deleted and only keeping two at any given moment. The literature from the Mac user guide states "time machine backs up your computer and keeps local snapshots and hourly backups for the past 24 hours, daily backups for the past month and weekly backups for all previous months."

Any idea why it's not keeping all my local snapshots past the last 2 days? This reads as though it should be keeping 30 days or so (a month) before deleting....

Or am I misinterpreting the Mac user guide?

If you're saying this is normal behavior, that's fine. Just want to make sure I don't have a bug in my system. I don't know anything about tech, but could it be because I've been connecting to my external hard drive daily? Is TM only going to keep the daily snapshots for longer if I stop connecting for a while (thus stopping the true daily backups)?

Thanks so much for your help.

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Answer 8

Link007 Author

Level 1

9 points

Jun 11, 2025 12:47 PM in response to leroydouglas

Oh I understand now. Thanks for your reply!

So basically Local Snapshots are only happening once per day (as opposed to once every hour), in order to match my settings for my actual backup disk, which is set to backup Automatically once per day. Is that correct? I was interpreting the Mac guide to say it would create local snapshots once per hour, regardless of actual backup disk settings, but I am guessing that's the part I misunderstood?

I also see that the guide says Local Snapshots are actually only kept for 24 hours, so only having two of them at any given moment makes sense.

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Answer 9

VSona

Level 1

12 points

Jun 24, 2025 6:03 AM in response to Link007

Well, I haven't seen this ever.

What would happen if you switch back to Hourly? Could any local snapshot come back?

For software problems, their reasons can't be instantly found out by Apple Support. They just list steps and let us to take until the problem is solved. If you do need hourly local snapshots + daily backup and you're really hurry…

I guess you'll probably use Time Machine restoration finally. It cleared buggy cached states many times for me. But it's not always worth the things we want. It may also cause data loss if not operating properly. (Important!)

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