Time Duration Calculator

Choose dates as well as clock times

The date removes the ambiguity that appears when a finish time is earlier on the clock. A task starting on Monday at 23:00 and ending on Tuesday at 02:00 lasts three wall-clock hours. Enter the actual finish date rather than trying to represent the task with two times from the same day.

The calculator subtracts the entered start from the entered finish. It requires the finish to be on or after the start. If the dates were entered in reverse order, correct them rather than taking the absolute value; preserving the order helps expose mistakes in a schedule or record.

Wall-clock time and elapsed time can differ

These fields describe local dates and times without a time-zone identifier. The calculation treats each date as a regular 24-hour day. It does not infer your location, attach UTC offsets or apply daylight-saving transitions. This is useful when you want the difference between two schedule labels, but it is a deliberate limitation.

For travel across time zones, a server incident spanning an offset change or a shift on a daylight-saving transition, use timestamps that identify their offsets and an elapsed-time method designed for them. Two local time labels alone are not enough to establish the exact real-world interval in every location.

Match the tool to the question

A duration includes nights, weekends and holidays between the endpoints. If you want only calendar dates, use the date difference calculator. If you want scheduled working dates, use the business days calculator and supply the applicable exclusions. If unpaid breaks should be removed from a single shift, use the work hours calculator instead of subtracting them implicitly from this result.

Common questions

Sources and references

• MDN: local date and time values ↗