Adding and Subtracting Time
Unlike base-10 mathematics, time operates on a sexagesimal (base-60) system inherited from ancient Sumerians. Because there are 60 seconds in a minute and 60 minutes in an hour, standard calculators fail when adding time.
The Base-60 Problem
If you try to add 1 hour 45 minutes and 2 hours 30 minutes on a normal calculator (1.45 + 2.30), you get 3.75, which is mathematically wrong for time. The correct math requires rolling over every 60 minutes into a new hour. (45m + 30m = 75m, which becomes 1 hour and 15 minutes, yielding a total of 4 hours 15 minutes).
Payroll and Timesheets
This calculator is specifically built for HR managers, freelancers, and pilots who need to track cumulative hours accurately. It safely crosses the midnight barrier (AM/PM shifts) and converts total tracked time into decimal formats for hourly wage multiplication.