Time Duration Calculator
Find the elapsed time between two clock times, even across midnight.
How to use this tool
- Enter start time (with optional date).
- Enter end time (with optional date).
- Calculate the duration in hh:mm:ss and totals.
How it works
Both times normalize to minutes; end minus start with a +24h correction when overnight, then decomposed back to h:m:s.
Tips
- For overnight shifts, either add dates or let the auto next-day logic run.
- Double-check AM/PM selection — the classic source of errors.
Limitations
Assumes a 12- or 24-hour clock as toggled; seconds optional.
Frequently asked questions
How do you handle times crossing midnight?
If the end time is earlier than the start, it's treated as the next day and a full span is computed.
Can I add a date to each time?
Yes — entering dates for both times removes all ambiguity, including across days.
What units are shown?
Hours:minutes:seconds plus total minutes and seconds.