Time Between Two Times Calculator and Formula

A time calculator between two times finds the elapsed duration from a start time to an end time, including when the end time falls on the following day. Enter both times in hours and minutes to get the difference in minutes and as hours, minutes, and seconds.

Formula

For times entered as minutes after midnight, elapsed minutes equal the finish time minus the start time, plus 1,440 minutes if the finish is on the next day:

Elapsed minutes = finish − start + (next-day indicator × 1,440)

• Start is the starting clock time expressed as minutes after midnight. For example, 9:00 a.m. is 540 minutes.
• Finish is the ending clock time expressed as minutes after midnight.
• Next-day indicator is 0 when both times are on the same day and 1 when the finish is on the following day.
• 1,440 is the number of minutes in 24 hours.
• Elapsed hours equal elapsed minutes divided by 60.

The inputs use a 24-hour total-minute scale rather than a typed clock format: 12:00 a.m. is 0, 12:00 p.m. is 720, and 11:59 p.m. is 1,439. The calculator’s default start, 540, represents 9:00 a.m.; its default finish, 1,020, represents 5:00 p.m. Choose whether the finish is on the same day or the next day.

Worked Example

Using the calculator’s defaults, the start is 540 minutes (9:00 a.m.), the finish is 1,020 minutes (5:00 p.m.), and the finish is on the same day, so the next-day indicator is 0.

1. Elapsed minutes = 1,020 − 540 + (0 × 1,440).
2. Elapsed minutes = 480.
3. Elapsed hours = 480 ÷ 60 = 8.00 hours.

The result is 480 minutes, or 8.00 hours, equivalent to 8 hours. The same result can be checked directly on a clock: 9:00 a.m. to noon is 3 hours, and noon to 5:00 p.m. is 5 more.

How to Enter Times and Read the Result

Convert each clock time to minutes after midnight before entering it. Multiply the hour by 60, then add the minutes. For instance, 2:35 p.m. is 14 × 60 + 35 = 875 minutes. For 12-hour clock notation, convert p.m. hours to 24-hour time by adding 12, except for 12:00 p.m.; for 12:00 a.m., use hour 0.

• 9:15 a.m. = 9 × 60 + 15 = 555 minutes.
• 12:30 p.m. = 12 × 60 + 30 = 750 minutes.
• 8:40 p.m. = 20 × 60 + 40 = 1,240 minutes.
• 12:10 a.m. = 0 × 60 + 10 = 10 minutes.

The first result is the duration in minutes; the second expresses that same duration in decimal hours. For a more familiar format, divide the minutes by 60: 95 minutes is 1 hour and 35 minutes, not 1.35 hours. Decimal hours use fractions of an hour, so 1.5 hours means 1 hour 30 minutes.

Overnight Times and Other Examples

Clock times alone do not establish which date an event happened. If the end clock reading is earlier than the start reading, the duration may cross midnight—but it could also indicate that the dates were entered incorrectly. Select the next-day option only when the finish is actually on the following day.

• Overnight shift: 10:00 p.m. to 6:00 a.m. the next day is 8 hours. In minutes, that is 360 − 1,320 + 1,440 = 480.
• Short same-day interval: 10:00 a.m. to 10:45 a.m. is 45 minutes.
• Same clock time: 8:00 a.m. to 8:00 a.m. on the same day is zero elapsed time. If the second 8:00 a.m. is the following day, the duration is 24 hours.

A duration can exceed 24 hours if the finish is on a later date, but a single next-day setting only adds one day. For a multi-day interval, calculate the total dates and hours explicitly or use date-and-time values that include both calendar dates. This calculator also assumes a conventional 24-hour day; daylight-saving clock changes can make elapsed real time differ from the simple difference between local clock readings.

Common Mistakes and Limits

• Mixing formats: Use minutes after midnight for both entries. Do not enter 9.30 to mean 9:30; 9.30 is a decimal number, not a clock-time conversion.
• Forgetting the day change: A finish earlier on the clock is not automatically treated as next day. Choose the next-day setting when appropriate.
• Confusing 12 a.m. and 12 p.m.: Midnight is 00:00; noon is 12:00. Their minute values are 0 and 720.
• Rounding too soon: Keep the exact minute difference for the calculation, then round a decimal-hour display only as needed. One minute is 1/60 of an hour, approximately 0.0167 hours.
• Ignoring dates or clock changes: The calculation does not know the calendar date, time zone, or daylight-saving transition. Use the actual dates and applicable local-time rules when those matter.

The arithmetic works equally well whether you describe duration in metric or US customary terms: time is measured in seconds, minutes, and hours, not in miles, kilometers, feet, or meters. If you are timing work or travel, the elapsed interval is not necessarily the same as paid time or time in motion; breaks and stops must be accounted for separately.

Frequently Asked Questions

How do I calculate the time between two times?
Subtract the start time from the finish time after converting both to minutes after midnight. If the finish is on the next day, add 1,440 minutes.

How many hours are between 9 a.m. and 5 p.m.?
There are 8 hours, or 480 minutes, between 9:00 a.m. and 5:00 p.m. on the same day.

How do I calculate hours worked overnight?
Enter the start and finish clock times and mark the finish as the next day. For example, 10:00 p.m. to 6:00 a.m. is 8 hours before accounting for any breaks.

How do I convert minutes to decimal hours?
Divide the number of minutes by 60. For example, 90 minutes is 1.5 hours; 1 hour 30 minutes is not 1.30 decimal hours.

Does the calculator account for breaks or daylight-saving time?
No. Subtract unpaid or other excluded breaks separately, and use date-aware time calculations when a daylight-saving change or time-zone difference affects the actual elapsed duration.

Related

• Date Calculator Between Two Dates: Subtract Days
• Date Calculator for Future Dates: How It Works
• Calculator Between Dates and Times: Find the Difference

in start | Start time (minutes after midnight) | min | 540 | 0
in finish | Finish time (minutes after midnight) | min | 1020 | 0
sel nextday | Finish is on | Same day=0, Next day=1
out duration | Time between | min | (finish - start + nextday * 1440)
out hours | Elapsed hours | h | duration / 60 | 2