10:00 PM to 6:00 AM duration
Here’s the exact time duration from 10:00 PM to 6:00 AM, crossing midnight into the next day.
Different times? Use the time duration calculator above.
About the time duration calculator
Time duration is the length of time between a start time and an end time on a 24-hour clock. The math is simple once both times are converted to total minutes since midnight: multiply the hour by 60 and add the minutes. Subtracting the start's total minutes from the end's total minutes gives the raw difference, but that alone breaks down whenever a shift or event crosses midnight, which is why this calculator uses a wraparound formula instead of plain subtraction.
The formula used here is durationMinutes = ((endTotalMinutes − startTotalMinutes) + 1440) % 1440, where 1440 is the number of minutes in a full day. Adding 1440 before taking the remainder (modulo) guarantees the result is always a positive number of minutes, whether the end time is later the same day or early the next morning. That result is then converted back into hours and minutes for the headline answer, and into decimal hours for anyone who needs a payroll-friendly number.
This calculator makes one assumption to resolve the same-day-versus-next-day ambiguity: if the end time you enter is numerically earlier than the start time (for example, start at 10:00 PM and end at 6:00 AM), it assumes the end time falls on the following day and calculates an overnight duration. If your end time is meant to be earlier on the same day — which would mean a negative duration — you'll need to swap the two times or treat it as a next-day calculation, since a calculator can't tell the difference from the numbers alone.
Decimal hours matter because most payroll and timesheet systems don't want "7 hours 30 minutes" — they want 7.5. To get decimal hours, divide the minute portion of the duration by 60 and add it to the hour portion (30 minutes ÷ 60 = 0.5, so 7 hours 30 minutes becomes 7.5 hours). This calculator does that conversion automatically alongside the more readable hours-and-minutes format.
This tool is built for single start/end pairs — a single shift, meeting, or trip. If you need to total up hours across multiple days or rows with different break deductions, the Time Card Calculator handles that multi-row case; this calculator focuses on getting one clean, accurate duration between two points in time.
Time duration calculator questions
How to calculate time duration, decimal hours, and overnight shifts.
How do I calculate time duration between two times?
Convert both times to total minutes since midnight (hour × 60 + minute), subtract the start from the end, add 1440 (minutes in a day), and take the remainder after dividing by 1440. That wraparound formula always gives a positive duration, even overnight.
How does this calculator handle a time duration that crosses midnight?
If the end time you enter is numerically earlier than the start time — for example, starting at 10:00 PM and ending at 6:00 AM — the calculator assumes the end time falls on the next day and returns an overnight duration (8 hours in that example) instead of a negative number.
How do I convert time duration to decimal hours for payroll?
Divide the minutes portion by 60 and add it to the hours. For example, 7 hours 30 minutes is 7 + 30/60 = 7.5 decimal hours. This calculator shows decimal hours automatically alongside the hours-and-minutes result.
What is 45 minutes in decimal hours?
45 minutes is 45 ÷ 60 = 0.75 decimal hours.
Does the time duration calculator account for AM and PM?
Yes — enter times using the 24-hour hour stepper (0-23), where 0 is midnight, 12 is noon, and 13-23 are 1 PM through 11 PM. The results display back in familiar 12-hour AM/PM format.
What's the difference between this and the Time Card Calculator?
This calculator finds the duration between one start and end time, which is ideal for a single shift, meeting, or trip. The Time Card Calculator totals hours across multiple rows (like a full workweek) and subtracts unpaid break time from each row before summing.