TimeMathNow
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Time Duration Calculator

Find how much time there is between two times, or two dates and times.

Clock format

Duration

0 hrs 0 min

Decimal hours
0.00
Total minutes
0
h:mm
0:00
Total seconds
0

    How to use it

    1. Type the start time and end time. Add seconds if you need them, for example 8:47:30.
    2. If the end time is earlier than the start, the calculator assumes it’s the next day, so 11:15 PM to 1:40 AM works without dates.
    3. For spans longer than a day, tick Include dates and pick a start date and end date.
    4. Read the duration in days, hours and minutes, plus total minutes and decimal hours. Copy or share the result if you need to send it on.

    Worked examples

    Between two times on the same day

    A delivery driver logs on at 8:47 AM and off at 5:12 PM.

    1. From 8:47 AM to 4:47 PM is exactly 8 hours.
    2. From 4:47 PM to 5:12 PM is another 25 minutes.
    3. Duration: 8 hrs 25 min, which is 505 minutes or 8.42 decimal hours (25 ÷ 60 = 0.4167).

    Across several days and a clock change

    An on-call technician is on duty from Friday, March 6, 2026 at 6:00 PM to Monday, March 9, 2026 at 7:30 AM, in a U.S. time zone that uses daylight saving time.

    1. By the clock, Friday 6:00 PM to Monday 6:00 PM would be 3 days, so Monday 7:30 AM is 2 days 13 hours 30 minutes.
    2. But clocks sprang forward one hour early on Sunday, March 8, 2026, so one hour never happened.
    3. Actual time on duty: 2 days 12 hrs 30 min (60.5 hours). The calculator uses your device’s time zone and shows a note when this happens.

    How it’s calculated

    duration = end − start

    • Without dates, both times are converted to seconds after midnight. If the end is smaller than the start, one day (86,400 seconds) is added, because the span must have crossed midnight.
    • With dates, the calculator builds a real date and time for each end in your device’s local time zone and measures the actual time that passed. That’s how a daylight-saving change gets counted correctly.
    • The result is split into days, hours, minutes and seconds. Decimal hours = total minutes ÷ 60, rounded to two places.

    Without dates, the longest span is just under 24 hours. Equal start and end times give zero; for a full 24-hour shift, switch on dates.

    Frequently asked questions

    How do I calculate the time between two times?
    Subtract the start time from the end time. If the minutes don’t subtract, borrow an hour as 60 minutes. For 9:50 AM to 2:15 PM: 2:15 PM is 14:15, so 14:15 − 9:50 = 13:75 − 9:50 = 4 hours 25 minutes.
    How many hours are there between 8 AM and 5 PM?
    Nine hours. Count 8 AM to 12 PM (4 hours) plus 12 PM to 5 PM (5 hours). If there’s a 1-hour unpaid lunch, that’s 8 hours of work.
    What happens if the end time is after midnight?
    Without dates, an end time earlier than the start time is read as the next day. 10:30 PM to 2:00 AM is 3 hours 30 minutes. For longer gaps, switch on Include dates.
    Does it account for daylight saving time?
    Yes, when dates are switched on. It uses your device’s time zone, so a span across the spring change is an hour shorter and one across the fall change is an hour longer, and you’ll see a note saying so. Times without dates ignore clock changes.