50 seconds to march

Instructions

March time should be provided as a decimal where the number before the dot is the number of minutes and the number after the dot represents the number of seconds. For instance, 5m4 becomes 5.04 (not 5.4) and 30 seconds becomes 0.30, or 0.3 if you like.

To use this to synchronise marches on attack targets, have each player in the group set their march and make sure each has between 1 and 19 minutes left when you signal a reference moment. This signal could be sent in a game chat channel, and when each participant sees it they should immediately memorise their remaining march time at that precise moment. They should then enter that time in this calculator and speed up at the exact moment the output tells them to do so.