Hours between two times or two dates — totals in hours, minutes and seconds.
An end time earlier than the start is counted as overnight (next day). For shifts with breaks and pay, use the Time Card Calculator instead.
Quick reference: 1 hour = 60 minutes = 3,600 seconds · 1 day = 24 hours = 1,440 minutes · 1 week = 168 hours.
How to use this tool
Pick 'Between two times' or 'Between two dates'.
Enter a start and end time (or date). An earlier end time counts as overnight automatically.
You get the duration as hours + minutes, decimal hours, total minutes, total seconds — and, for dates, weeks too.
Copy the duration for a timesheet, invoice or schedule.
Formula & worked example
Worked example (times): 09:30 to 17:45 = 8 hours 15 minutes = 8.25 hours = 495 minutes = 29,700 seconds. Worked example (dates): 1 January 2026 to 8 January 2026 = 7 days = 168 hours = 10,080 minutes = 604,800 seconds = exactly 1 week. And the single most-asked conversion on this page: how many seconds in an hour? 60 minutes × 60 seconds = 3,600 seconds.
Limitations — read this before you rely on it
Time durations assume the same day unless the end time is earlier (then overnight is assumed) — they do not know which calendar day you meant, so always double-check overnight spans. Date gaps count whole calendar days and ignore daylight-saving changes and time zones: a week across a clock change is 168 hours here, not 167 or 169 local hours. For payroll with breaks, overtime and pay, use the Time Card Calculator instead of this plain duration tool.
Frequently asked questions
Subtract the start time from the end time. 09:30 to 17:45 is 8 hours 15 minutes, or 8.25 hours in decimal. If the end time is earlier than the start (for example 22:00 to 06:00), it counts as overnight and 24 hours are added first, giving 8 hours.
60 minutes × 60 seconds = 3,600 seconds in an hour. A day is 24 × 3,600 = 86,400 seconds and a week is 604,800 seconds.
An hour calculator and an hours calculator are the same job — one duration, just singular vs plural phrasing. This page covers both: use 'between two times' for a single span, or 'between two dates' for multi-day gaps, and you get hours, minutes and seconds together.
Dates count whole calendar days between the two dates, end date not included — the same convention as 'how many days until' counts. 1 January to 8 January is 7 days. If you need to include both endpoints, add 1 to the result.
Yes for gaps that ignore clock changes, but daylight-saving days are 23 or 25 hours long in real clock time. This calculator counts calendar days (24 hours each), so a week spanning a clock change is still 168 hours here even though one local day was shorter or longer.