Time Duration Calculator
Total hours and minutes between one date and time and another: a long shift, a trip, an on-call stretch. Daylight saving handled.
When to use it
Use this when a span runs over more than one calendar day: a 36-hour on-call weekend, a long-haul drive, a hospital double. For an ordinary shift, the hours calculator is quicker, and it already copes with finishing after midnight. To add several durations together, use the hours and minutes calculator.
How elapsed time is measured
Each date and time is converted to an exact moment using your time zone’s rules from the IANA time zone database built into your browser. The difference between the two moments is the real elapsed time. That is why a span across the US spring-forward night shows 60 minutes less than the clock difference: that hour never happened.
Questions people ask
How do I calculate the duration between two times on different days?
Count the whole days between the dates, multiply by 24, then add the difference between the clock times. From Monday 8:00 PM to Wednesday 6:30 AM is 1 full day (24 h) plus 10 h 30 min = 34 h 30 min, if no daylight-saving change falls in between.
Does this time duration calculator account for daylight saving time?
Yes. Choose the time zone and it measures real elapsed time, so a span across the spring change is an hour shorter than the clocks suggest and one across the autumn change is an hour longer.
How many hours are in a week?
168 hours: 7 days × 24 hours. A standard 40-hour work week is just under a quarter of that.
What if a time happens twice when the clocks go back?
Between 1:00 and 2:00 AM on the night US clocks fall back, each minute occurs twice. The calculator uses the first occurrence and tells you so.