AM hours are the same in both 12-hour and 24-hour time. For example, 1:00 PM would be 13:00 in 24-hour time. A cool little 1 Hour Timer! Determine whether the number of minutes is larger in the starting time or the ending time. The timer will tell you when your 1 hour has run out. Online 1 hour 20 minute timer with alarm, free to use and easy to share Allows you to countdown time from 1 hour 30 min to zero. 1 hour 23 minute equal 4980000 Milliseconds. For PM hours, add 12 to the number to convert it to 24-hour time. Preset timer for one hour twenty minute. If you have sound notification the timer will tell you when time is up. Allows you to countdown time from 1 hour 23 min to zero. Preset timer for one hour twenty-three minute. If the times are not already in 24-hour time, convert them to 24-hour time. 1 min - : 3 min - : 5 min - : 10 min: 15 min - : 20 min - : 30 min - : 1 h Timer details Preset timer for one hour thirty minute. Best online countdown timer with buzzer. Easy to adjust, pause, restart or reset. You can keep the timer running in the background if you for example open a new tab. Try the Fullscreen button in classrooms and meetings :-) 1 hour 20 minute equal 4800000 Milliseconds. 1 hour 23 minute equal 4980000 Milliseconds. Allows you to countdown time from 1 hour 23 min to zero. Simple to use, no settings, just click start for a countdown timer of 1 Hours. Allows you to countdown time from 1 hour 20 min to zero. ... 1 sec 5 sec 10 sec 15 sec 20 sec 30 sec 40 sec 45 sec 50 sec 60 sec 90 sec Similar Timers 1 h 1 h 1 sec 1 sec 1 min 1 min 2 h 2 h 2 sec 2 sec 2 min 2 min 3 h 3 h 3 sec 3 sec 3 min 3 min. Sound notification after 60 minutes (alarm) is optional. Set timer for 1 Hour 30 Minutes and use it to cook food, remember to call back, to take breaks, etc. Easy to adjust, pause, restart or reset. Easy to adjust, pause, restart or reset. How to use 1 hour timer. Minute timer ⏰ set online countdown timer and track your time ⏰ Minute timer. Easy to adjust, pause, restart or reset. 1 hour 20 minute is about 80 Minutes. Preset timer for one hour twenty-three minute. start. It will keep counting minutes and seconds upward instead. 1 hour 30 minute equal 5400000 Milliseconds 1 hour 30 minute equal 5400 Seconds 1 hour 30 minute is about 90 Minutes 1 hour 20 minute equal 4800 Seconds.