The Start Time Calculator does one thing and one thing well. If you have a variable length activity that needs to stop at a specific time, the Start Time Calculator will tell you when you should start in order to finish on time.
For example, do you have a 26 minute and 47 second music set to play and you need to be done by 5:18 PM? No problem! Enter the set length and end time in the app and it will display the time you need to start at the top of the app in large numbers. That would be 4:51:13 PM by the way.
Its really that easy.