How it works
- You enter a start time and an end time, such as 9:00 AM and 5:30 PM, or 21:30 in 24-hour form. Seconds are optional, as in 13:05:20. You can also enter how many days later the end falls and a break in minutes to take off.
- Each time is turned into seconds after midnight: hours times 3600, plus minutes times 60, plus seconds. This uses the facts that 1 hour is 60 minutes or 3600 seconds and 1 minute is 60 seconds, from the units dictionary at ibiblio.org.
- The start is taken from the end, and each day later adds 24 hours (86,400 seconds), since a day is 24 hours. If days later is 0 and the end time is earlier than the start, the end is treated as the next day, so a shift from 22:15 to 06:05 is 7 h 50 min.
- The break is then taken off. The result shows the duration in hours and minutes (seconds only when they are not zero), total minutes and decimal hours rounded to 2 decimals, total seconds, and whether the end falls on a later day.
Questions
How do I find the hours between two times?
Turn both times into minutes after midnight and subtract. For 9:00 AM to 5:30 PM, 9:00 AM is 540 minutes and 5:30 PM is 1050 minutes, so the gap is 510 minutes. Divide by 60 to get 8.5 hours, which is 8 h 30 min.
What if my shift goes past midnight?
Leave days later at 0 and type the end time as it shows on the clock. If the end time is earlier than the start time, the tool treats it as the next day. For example, 22:15 to 06:05 is 470 minutes, or 7 h 50 min.
What are decimal hours?
Decimal hours show minutes as a part of an hour, which many timesheets ask for. Since an hour is 60 minutes, 30 minutes is 0.5 hours and 50 minutes is about 0.83 hours. The tool rounds decimal hours to 2 decimals.
How do I take off a lunch break?
Enter the break in minutes. It is taken off the total. A shift from 08:30 to 17:00 with a 30 minute break is 8 h 0 min. If the break is longer than the time span, the tool says so and shows no result.
Can I use seconds or 24-hour times?
Yes. Type times like 13:05:20 or 1:05:20 PM. You can also type 24:00 as the end time to mean the end of the day. A start of 13:05:20 and an end of 14:47:50 gives 1 h 42 min 30 s.
Why does a two day span show as 47 h and not in days?
Timesheets and logs usually count hours, so the main result stays in hours. From 10:00 to 09:00 two days later is 47 h 0 min. When the total is 24 hours or more, a second line also shows it as days, hours and minutes.
Does it handle time zones or daylight saving time?
No. It counts clock time. On a night when clocks change for daylight saving, the real time that passed can differ by one hour, and the tool does not adjust for that or for time zones.
Do I need to give my email?
No. The result shows on screen as soon as you type the times. The email box below the result is optional, if you want a copy sent to you.