Date, time and shift planning

Time Duration Calculator

Calculate exact elapsed time, overnight shifts with breaks, or a new date after adding or subtracting a duration. Compare calendar time with total hours, minutes and seconds.

Time Duration Studio

Choose a calculation mode. All calculations run privately in your browser.

Breaks

Add one or more breaks. Unpaid breaks are deducted from the result; paid breaks are shown but remain included.

Duration result

Elapsed time–

–

Before unpaid breaks–
After unpaid breaks–
Total hours / Decimal hours–
Total minutes / Total seconds–
Paid breaks–
Unpaid breaks deducted–

Time-zone or clock-change effect: –

Visual duration timeline

StartUnpaid break shareEnd

Duration breakdown

0Days
0Hours
0Minutes
0Seconds

The entered dates, times and breaks stay in your browser and are not sent by this calculator.

Exact time and calendar time

Exact elapsed time counts the real seconds between two moments. Calendar difference describes the interval using calendar years, months and days, whose lengths are not constant.

Overnight shifts and breaks

In work-shift mode, an end time that is earlier than the start is automatically placed on the following day. Only unpaid breaks reduce the net duration.

Time zones and daylight-saving changes

Choose the relevant time zone for each date-time. The exact result uses the corresponding UTC moments, so a clock change can make a local interval one hour shorter or longer.

Useful presets and examples

  • 09:00 to 17:00 with a 30-minute unpaid break equals 7 hours 30 minutes.
  • 22:00 to 06:00 is automatically treated as an 8-hour overnight shift.
  • Adding one calendar month to a date respects the actual length of the destination month.

Time-zone reference

Named time zones follow the IANA Time Zone Database. Results involving daylight-saving transitions are calculated from the selected zone and date, but local rules can change in the future.

Time duration calculator FAQ

What is the difference between elapsed time and calendar difference?

Elapsed time is the exact number of seconds between two moments. Calendar difference expresses a same-zone interval in years, months, days and smaller units.

How does the calculator handle an overnight shift?

In work-shift mode, an end time that is equal to or earlier than the start time is placed on the following calendar day.

Which breaks are subtracted?

Only breaks marked unpaid are deducted. Paid breaks remain part of the net work duration and are displayed separately.

Can different time zones change the result?

Yes. Two identical-looking local times can represent different UTC moments, and daylight-saving changes can also alter the exact elapsed duration.

What happens when I add one month to January 31?

The result is clamped to the final valid day of the destination month rather than overflowing into a later month.

Are my dates stored?

No. The calculation, copied text and calendar file are created locally in your browser.