Time Calculator
Free time calculator: the duration between two times, or add and subtract hours and minutes from a time — with overnight and next-day handling. In-browser.
updated
- ✓ Runs in your browser — nothing uploaded
- ✓ No sign-up
- ✓ Free, no limits
If the end time is earlier than the start, it’s treated as the next day — so 11:00 pm to 1:00 am reads as 2 hours, which is what you want for a night shift.
This time calculator answers the two clock questions that trip people up. How long is it from one time to another? And what time is it a certain number of hours and minutes before or after now? Pick a mode, enter the times, and the answer appears — no counting on fingers across the noon boundary.
The duration mode handles the case that breaks naive subtraction: when the end time is earlier than the start, it treats it as the next day. So 09:00 to 17:30 is 8 hours 30 minutes, and 11:00 pm to 1:00 am reads as 2 hours, not minus 22 — exactly what you want for a night shift or a sleep window. It shows the result three ways: hours and minutes, total minutes, and decimal hours (handy for timesheets and billing).
The add/subtract mode moves a starting time forward or backward by any hours and minutes, and flags when the result lands on the next or previous day. Use it for arrival times, cooking schedules, or working out when to leave. Everything runs in your browser — the times you enter are never sent anywhere, and it works offline.
Frequently asked questions
How do I calculate the hours between two times?
Convert both to minutes past midnight and subtract; if the end is earlier, add 24 hours first. The duration mode does this and shows the gap as hours-and-minutes, total minutes and decimal hours.
Does it handle times that cross midnight?
Yes. If the end time is earlier than the start, it's taken as the next day — so 11:00 pm to 6:00 am correctly reads as 7 hours, which is what shift and sleep calculations need.
Can I add hours and minutes to a time?
Yes — the add/subtract mode moves a start time forward or backward by any amount and tells you if the result rolls over to the next or previous day (for example 11:00 pm plus 3 hours is 2:00 am, +1 day).