If you can lay your hands on a Bally WIzard-type pinball machine - the score displays can be converted and display the time, date, year and alarm time for a clock which will be added to the machine. But don't panic - this isn't a permanent modification. Instructables user alanamon demonstrates how to mod the pinball machine with an Arduino, GPS shield (to receive the time data) and some relays which the Arduino controls to turn the machine on and off at certain predetermined times. See it in action in the following video:
If your pinball machine is in the basement or other fun, dank place - a GPS clock won't cut it. Instead consider using our super-accurate real-time clock module. Based on the DS3232, it has a temperature-controlled crystal oscillator for accurate time keeping, battery backup and 236 bytes of non-volatile memory for user data. For more information, see our modules page.