Time Duration Calculator

Find the hours, minutes, and seconds between two times. Use the same-day form for clock times, or add dates below when the span crosses more than one day.

Time Between Two Dates

Measure days, hours, minutes, and seconds between two date-times. To add or subtract time from a single date, use the time calculator.

How to calculate the duration between two times

1. Enter a start time and an end time (include seconds if you need them).
2. Spanning more than one day? Fill in start and end dates. Otherwise the tool assumes the same day and rolls past midnight when the end is earlier on the clock.
3. Read the span in days, hours, minutes, and seconds, plus decimal hours for timesheets.

Duration is end minus start. With blank dates and an earlier end clock, one day is added so 10:00 PM to 6:00 AM returns 8 hours, not a negative value.

How to calculate time duration manually

Put both times in 24-hour form. AM hours stay the same; for PM hours add 12 (1:00 PM becomes 13:00). Then subtract start from end, keeping hours and minutes on each side of the colon.

Example: 13:57 minus 9:22 is 4 hours and 35 minutes when the end minutes are larger. When start minutes are larger, borrow one hour: turn 13:57 into 12:117, then subtract 9:58 to get 3:59.

For overnight spans, add 24 hours to the later clock before subtracting. The same borrow rules apply if you also track seconds.

Hours and decimal hours

Payroll and invoicing often want decimal hours, not hours and minutes. Eight hours and thirty minutes is 8.5 decimal hours because 30 ÷ 60 = 0.5. This calculator shows both forms so you do not convert by hand.

For shift length with break minutes, the hours calculator subtracts unpaid breaks in one step.

What you can use it for

• Work hours and payroll: clock-in to clock-out spans, including overnight shifts.
• Billing and projects: turn a client session into billable hours and minutes.
• Study and focus blocks: measure how long a session actually ran.
• Cooking and events: timings that run past midnight or across several days.

FAQ

What is a time duration calculator?

It finds how much time passes between a start and an end. You enter two times (and optional dates) and get the gap in hours and minutes, in seconds, and as decimal hours.

How does it handle times that cross midnight?

Leave dates blank. If the end clock is earlier than the start, the calculator treats the end as the next day and adds 24 hours. So 22:00 to 06:00 returns 8 hours.

Can it calculate across multiple days?

Yes. Add start and end dates and it measures the exact span between the two date-times, including whole days, then shows days, hours, minutes, seconds, and total hours.

How do I convert minutes to decimal hours?

Divide minutes by 60. Fifteen minutes is 0.25 hours; forty-five minutes is 0.75 hours. The Total hours line already shows that conversion.

Does the calculator count seconds?

Yes. Enter seconds in the fields and the duration includes them in the breakdown and in Total seconds. Leave seconds at zero if you only need hours and minutes.

Can I use it for timesheets and payroll?

Decimal hours match what many payroll systems expect. For day-by-day clock entries with breaks and overtime, use the time card calculator.