AlarmPick

Hours calculator

Enter a start time, an end time, and a break in minutes. AlarmPick subtracts the break from the clock span and shows hours and minutes plus decimal hours. An earlier end time continues into the next day. The same start and end are 0 hours, not 24. This is a clock-time interval, not a dated timesheet, and it does not apply daylight saving time or decide pay. The times are not saved. It is free to use.

What is an hours calculator?

The AlarmPick hours calculator measures the minutes between two times of day and subtracts a break. The inputs are a start time, an end time, and a break in whole minutes. The outputs are the gross duration, the break, the net duration, and decimal hours. It does not look up a time zone and it does not judge payroll or labor rules.

How the calculation works

Each time becomes minutes after midnight. 09:30 is 570 minutes. If the end is later the same day, the span is end minus start. If the times match, the span is 0. If the end is earlier, the span is the rest of the day plus the end time. Swap exchanges the two times, so 09:00 to 17:00 becomes an overnight span from 17:00 to 09:00. Break chips set 0, 15, 30, or 60 minutes. Reset returns to 09:00, 17:00, and a break of 0. The break is then subtracted. Whole hours are the net minutes divided by 60, and the leftover is the remaining minutes.

Overnight hours

22:00 to 02:00 is 4 hours. The calculator treats the end as the next time that clock shows, without a calendar date. 23:59 to 00:00 is 1 minute. A real night that gains or loses an hour because clocks change is outside this page.

Break deduction

09:00 to 17:30 is 8 hours 30 minutes before a break. A 30-minute break leaves 8 hours 0 minutes, which is 8.00 decimal hours. A break of 0 leaves the gross duration unchanged. A break equal to the span leaves 0. A longer break produces a message instead of a negative time.

Decimal hours

Decimal hours are the net minutes divided by 60. 7 hours 30 minutes is 7.50. 7 hours 20 minutes is 7.33. The stored minute count stays exact. Only the decimal line is rounded to two places.

Same start and end

09:00 to 09:00 is 0 hours 0 minutes and 0.00 decimal hours. Equal times do not mean a 24-hour span. A break above 0 on that span is rejected because the break is longer than the time between the two clocks.

Common uses

  • The length of a same-day span, such as 09:00 to 17:00.
  • A span that crosses midnight, such as 22:00 to 06:00.
  • A break subtracted from that span, shown in hours and minutes and as decimal hours.

Limitations

  • This page compares two clock times. It does not attach them to a calendar date.
  • Daylight saving time and time-zone changes do not change the result. 22:00 to 02:00 stays 4 hours.
  • The same start and end are 0 hours. A full day is not inferred.
  • The longest span is 23 hours 59 minutes, from a time to one minute before it returns.
  • The calculator does not decide wages, overtime, or legal working time.
  • The fields start at 09:00, 17:00, and a break of 0. Those are fixed examples, not the current time, and they are not saved on this device.

Questions

How many hours are between two times?

Enter the start and end, set the break to 0, and choose Calculate. The net line is the clock span in hours and minutes.

How do I calculate hours worked?

Enter the start, the end, and the break in minutes. The net duration is the span minus that break. This page does not decide pay.

How does the calculator handle an overnight shift?

If the end clock time is earlier than the start, the span continues to that time the next day. 22:00 to 02:00 is 4 hours.

What happens when the start and end times are the same?

The span is 0 hours and 0.00 decimal hours. It is not treated as 24 hours.

How do breaks affect the result?

The break is subtracted after the clock span. A break longer than that span shows a message and no negative time.

How do I convert hours and minutes to decimal hours?

Divide the net minutes by 60. The decimal line shows two places: 30 minutes is 0.50 and 20 minutes is 0.33.

Does this calculator account for daylight saving time?

No. It uses the two clock times only. A night when the clocks change length is not a different result here.

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