Turn the minute hand forward from the current time and you get "minutes after"; turn it backward and you get "minutes before." But when the minutes go over 60 or under 0, the hour hand has to move too. Use the sliders to change the current time and the elapsed time, and compare the two clocks.
Minutes After: Add the number of minutes set by the slider to the current time. If the sum goes over 60 minutes, the hour hand moves ahead to the next hour.
Current hour2 o'clock
Current minute50 min
Minutes to add20 min later
Current time
20 min later ➡️
Resulting time
Minutes Before: Wind the current time back by the number of minutes set by the slider. If you wind back more than the current minute count, the hour hand moves back to the previous hour.