DateDelta

Time Duration Calculator

Enter a start and end time — get the exact elapsed time, even if it crosses midnight.

Start hour (0–23)

Start minute

End hour (0–23)

End minute

Duration (hours)

8.5

If the end time is earlier than the start time, we assume it wraps past midnight.

Total minutes: 510

What you entered

Start hour (0–23): 9Start minute: 0End hour (0–23): 17End minute: 30

1
Difference between end and start time
17:30 − 09:00= 510 minutes
2
Convert to hours and minutes
510 ÷ 60= 8h 30m

Result

Duration (hours): 8.5

From 9:00 to 17:30 is 510 minutes.

Duration between two clock times

The duration in hours and minutes, including shifts that cross midnight.

Start	End	Total minutes	Duration
8:15	12:45	270	4h 30m
9:00	17:00	480	8h 0m
9:30	17:15	465	7h 45m
13:00	21:30	510	8h 30m
22:00	6:00	480	8h 0m

The last row crosses midnight, and the calculator handles it by rolling into the next day rather than returning a negative duration - a night shift from 22:00 to 06:00 is 8 hours, not minus 16. That is the case most manual calculations get wrong. Note the result is elapsed time and does not deduct breaks: for paid hours, subtract unpaid break minutes, which the hours worked calculator does directly.

Handles overnight shifts automatically

If the end time is earlier than the start time (like a 10 PM to 6 AM shift), the calculator assumes the end time falls on the next day rather than showing a negative duration.

Time duration vs. date difference

This calculator works within a single day (or overnight), measuring hours and minutes. For spans measured in days, weeks, or years, use a date difference calculator instead.

Frequently asked questions

My shift starts at 10:45 PM and ends at 7:15 AM — how long is that?

That's 8 hours 30 minutes. The calculator detects the overnight crossing automatically: from 10:45 PM to midnight is 1 h 15 min, plus midnight to 7:15 AM is 7 h 15 min, totaling 8 h 30 min.

How is this different from the Hours Worked Calculator?

This calculator measures raw elapsed time between any two clock times. The Hours Worked Calculator also subtracts unpaid break time and outputs decimal hours for payroll. Use this one for general time spans, the other for shift-based pay calculations.

Does this handle durations longer than 24 hours?

No — it's designed for within-a-day or single overnight spans. If the start and end times are identical, it returns 0, not 24 hours. For multi-day durations, use a date difference calculator instead.

Why does the result show 0 when both times are the same?

Identical start and end times produce 0 h 0 min because the calculator assumes no time has passed. If you mean a full 24-hour span, set the end time one minute later or use a date-based calculator that counts whole days.