Set a timer for 20 minutes to wake you up in 20 minutes. This is a free and easy-to-use countdown timer that allows you to set the hour, minute, and second for the online countdown. Simply start the timer, and it will alert you when 20 minutes have passed. Alternatively, you can set a specific date and time to count down to (or from) an event. Begin your 20 minutes timer now for a quick and precise reminder.