: : OR
Instructions

1. Enter a duration in any of the first three fields (or all of them).
2. To normalize the first three fields, click Normalize (e.g. 75 seconds becomes 0:1:15).
3. To add or subtract times, fill out another time on the left and hit the plus or minus button.
4. To multiply or divide, enter a number on the right and hit the multiply or divide button.
5. In all cases, the result will be displayed at the bottom.

Example: You want to know how long 4673 seconds is. Enter 4673 in the third field at the top and hit Normalize. The result will be shown at the bottom (in this case, 1:17:53, or 1 hour, 17 minutes and 53 seconds.

History

I wanted to see how long it would take me to do something 15 times, knowing that it took me about 40 seconds to do it each time. I also wondered how much time I spent over the course of a year doing a small task each day, like waiting at a stop light. I didn't find any convenient and quick solutions to calculate those values, so I wrote this.