This is a previously reported issue where Screen Time background processes fail to pause when the Mac goes to sleep. It can occur because a background process (like a Safari webpage background script or Finder activity) keeps ticking, inflating your usage to exactly 23 hours 59 minutes.
You can completely isolate and purge the corrupted Mac reporting database without affecting your iPhone history by following these steps:
Clear the Corrupted Local Database
You need to forcefully wipe the local database files tracking this phantom activity.
- In Finder, Press Command + Shift + G to open the "Go to Folder" window.
- Paste the following path and press Return
~/Library/Application Support/
- Look for a folder named ScreenTime or com.apple.screentime.
- Move that folder to the Trash.
- Empty your Trash and restart your Mac.
- Your Mac will recreate that folder.
Clear Cloud Synced Glitches via Safe Toggle
To prevent the Mac from pulling the 24-hour glitch back down from iCloud, safely toggle the local tracking.
- Go to System Settings > Screen Time.
- Scroll down, click App & Website Activity, and Turn It Off.
- Leave it off for at least 10–15 seconds to allow iCloud to register the removal.
- Turn App & Website Activity back on.
Identify the Invisible Culprit
If the 24-hour bar returns tomorrow, check the lower section of your Screen Time menu for specific websites or background processes. If an open Safari tab with an aggressive ad script or video player is running, Screen Time registers it as active even while the display is asleep. Closing out background website tabs before putting your iMac to sleep often prevents the issue from triggering again.
More info from Apple: Screen Time on Mac - Apple Support
User level: Level 1 (4 points)
