Time Duration

Add and subtract hours, minutes, and seconds.

Loading tool

This tool runs in your browser. Nothing is uploaded.

Add a list of durations, or enter a start and end clock time. Crossing midnight is treated as the next day unless you say otherwise.

How to use this tool

  1. Set the dates or duration. Pick the clocks, dates, or timer length you need.
  2. Start or calculate. Run the timer or read the difference. Time zones use this browser.
  3. Copy the result. Copy timestamps or calendar values into your notes.

Formats

Accepts 1h 30m, 90m, and 1:30:00. Mixed rows in a list are converted to seconds, then summed.

Frequently asked

Can I sum a timesheet?

Paste one duration per line. The total is in hours and minutes.

Does it deduct a lunch break?

Add a negative duration or a break field.

Are seconds rounded?

You can round to the next minute for billing-style estimates.

Is this payroll?

No. It is duration math.

Can I convert to decimal hours?

Yes. 1:30 becomes 1.5.