Easiest solution I have for (time)(time)=duration
I always look here for solutions to my ideas before I spend too much time on them. I was not able to find a simple solution for doing calculations with time. Honestly, after my initial search, I ended up exporting to excel to do the math, then importing back in.
Long story short, here is a single formula to subtract start time from end time and provide a duration. Times are HH:MM 24 hour format. Works great for tracking time spent on different projects via a mobile form.
Snip with formula and column names for reference: https://ibb.co/dBYrDGJ
Formula for copy paste:
=(IF((VALUE(RIGHT([End time]@row, 2))  VALUE(RIGHT([Start Time]@row, 2))) > 0, (VALUE(LEFT([End time]@row, 2))  VALUE(LEFT([Start Time]@row, 2))), (VALUE(LEFT([End time]@row, 2))  VALUE(LEFT([Start Time]@row, 2)))  1)) + ":" + (IF((VALUE(RIGHT([End time]@row, 2))  VALUE(RIGHT([Start Time]@row, 2))) < 0, 60 + (VALUE(RIGHT([End time]@row, 2))  VALUE(RIGHT([Start Time]@row, 2))), (VALUE(RIGHT([End time]@row, 2))  VALUE(RIGHT([Start Time]@row, 2)))))
Answers

Here is a link to a number of time based solutions that you may want to check out if you ever have any other bits you need to solve for:
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