How random that it looks like my old Casio! The Time Calculator allows adding and substracting time values in the sexagesimal system (where the base value is 60).
If you ever tried to add 17 minutes to 1.8 hours in your head, then you probably know that this can be error-prone.
Unfortuntely, most available calculators for Windows don't support the sexagesimal system. That's why I made this calculator. So, if you need to calculate with time values, you should really try the Time Calculator.
The decimal system is of course also supported.
Current version: 18.104.22.168
The Time Calculator comes without installer. Just download an run it.
If you like the Time Calculator and find it useful, feel free to donate.