Essentially, if your device were to sit around for 3 consecutive days (72 hours), Android would recognize that and then automatically restart it. Why, you ask?

If you leave your Android phone or tablet locked for three consecutive days, your device will automatically restart. You'll need to re-enter your passcode to open the device.

OnePlus is making a considerable change with its Android 16 update which will require users to fill out an application before having the ability to unlock their bootloader.