If I understand it correctly, it does that when the run-time clock loses power. So next time you switch it on it does not know what the current time is and so it asks you.

You can trigger it by for example taking the battery out. Which, of course, is what you need to do to swap the SIM card.

You can also trigger it by draing the battery comlpletely. The USB port on my laptop does that. Instead of charging the phone it drains it.

Sorry, but I do not know how to disable it or whether it is even possible. But it might not be a good idea anyway as the system time will be wrong.