Clock interval · Overnight option · Break subtraction

Time Duration Calculator

Measure a nominal wall-clock interval, explicitly choose whether it crosses midnight, and subtract one break. Gross and net duration remain visible, while time-zone and payroll policy claims stay outside the calculation.

Calculate durationHours and minutes · Local processing
overnight shift
start  22:30
end    06:15 next day
gross  7 h 45 min

Crossing midnight is explicitBreak is subtracted afterward

Nominal clock arithmetic with visible assumptions

Calculate gross time, then subtract one break

Enter start and end clock times, select overnight only when the end occurs on the next date, and enter a nonnegative break duration. The calculator reports gross and net minutes plus an hours-and-minutes presentation.

Loading the time duration calculator…

Enable JavaScript to enter clock times, overnight behavior, and a break. The arithmetic contract, DST limitations, examples, and FAQ remain readable below.

An earlier clock label needs another fact

Overnight mode places the end on the next calendar day

A clock time alone repeats every day. If the start is 22:30 and the end is 06:15, subtraction cannot tell whether the input is invalid, spans overnight, or refers to unrelated dates. Selecting overnight states that the end belongs to the following day, yielding a nominal gross interval of seven hours and 45 minutes.

When both clock labels are equal, same-day mode represents zero duration. Overnight mode can represent a full 24-hour wall-clock cycle. The distinction is deliberate; the calculator does not guess from an employment context or automatically choose the larger interval.

The break is a duration, not another clock endpoint. It is subtracted once after gross duration is found. Showing gross, break, and net independently prevents a copied result from hiding whether lunch or another pause was already removed.

Gross
Nominal interval before a break.
Overnight
End clock time belongs to the next date.
Break
One nonnegative duration subtracted once.
Net
Gross minus break, never below zero.

Wall-clock labels do not identify instants

DST requires a date, time zone, and offset history

A spring-forward night can omit local clock labels, while a fall-back night can repeat them. “01:30 to 03:30” might represent one, two, or three elapsed hours depending on the date and named zone. Because this page accepts only nominal clock times and an overnight choice, it cannot determine which offset transition applies and does not pretend to do so.

QuestionThis pageRequired for more
Wall-clock differenceSupported.Start, end, and overnight selection.
DST elapsed timeNot inferred.YYYY-MM-DD dates, IANA zone, and zone database.
Multiple breaksEnter their verified sum as one break.Separate schedule records for detailed auditing.
Payroll resultNot decided.Rounding, contracts, and applicable labor policy.

Keep arithmetic and policy in separate steps

Common duration workflows

  1. 1

    Same-day session

    09:00 to 17:00 is eight gross hours. Enter a 30-minute break to report seven hours 30 minutes net.

  2. 2

    Overnight shift

    Choose overnight for 22:30 to 06:15. Do not use the option merely to turn an accidental reversed input into a positive number.

  3. 3

    Multi-day project

    Use Days Between Dates for calendar spans. This tool intentionally supports only same-day or next-day clock intervals.

Need working dates rather than hours?

Exclude configured weekend weekdays and user-entered holiday dates with a schedule-specific calculator.

Open the Business Days Calculator →

Clock-duration answers

Time duration calculator FAQ

How does the calculator handle an end time earlier than the start?

When overnight mode is selected, the end time is interpreted on the following calendar day. Without that selection, an earlier end is invalid rather than silently assumed to cross midnight.

How is a break subtracted?

One nonnegative break duration is subtracted once from the gross wall-clock interval. A break longer than the gross interval is rejected rather than producing a negative worked duration.

Does the calculator account for daylight saving time?

No. Clock times without a date and IANA time zone cannot identify a DST transition. This page performs nominal wall-clock arithmetic; use zoned timestamps and authoritative zone data for elapsed-time work across a transition.

Is 09:00 to 17:00 eight hours if there is a lunch break?

The gross interval is eight hours. With a 30-minute break the net result is seven hours 30 minutes; with a 60-minute break it is seven hours. Enter the break explicitly.

Can this calculator determine payable work time?

No. It supplies arithmetic only. Rounding, paid breaks, overtime, split shifts, on-call time, labor rules, contracts, and payroll policies must be applied by the responsible employer or system.