Activity hours help Windows 10 determine when you are using the PC. Within activity hours, the computer is not rebooted.
Updates are downloaded, but the request to complete the updates by a reboot is made outside of activity hours.
By default, Windows 10 applies an active hour set. This is often from early morning 10:00 to 18:00 early evening. To set the active hours more precisely, you can have Windows 10 set the active hours based on activity.
As the option suggests, Windows 10 will then apply the active hours to the user’s activity. This way, Windows can adapt, and Windows Update will send you restart requests less often when using the computer.
If you do not want to receive more restart requests, you can disable Windows update notifications altogether.
Automatically adjust active hours for this device based on activity
Click on the Start menu button. Then click Settings on the left.
In the Settings, click on “Update & Security”.
In the left menu, click “Windows Update” and then click “Change active hours” in the right pane.
Change the option “Automatically adjust active hours for this device based on activity” to “On.”
Set active hours to let us know when you usually use this device. The device will not automatically reboot during this time.
The usage times only apply to installing updates. Having the usage times set automatically gives you no further control over when updates are downloaded.
I hope this has helped you. Thank you for reading!