Time Duration
Elapsed time between two clock times.
The Time Duration Calculator finds the exact duration between any two times of day — down to the second. Enter a start time and end time to get the elapsed time in hours, minutes, and seconds. You can also add a duration to a start time to find the end time, or sum multiple time intervals together for total time tracking. The calculator handles overnight durations (crossing midnight) automatically. Ideal for tracking work sessions, timing events, calculating billing increments, cooking timers, and travel time planning.
Time Duration
Examples
Office Work Session: 9:00 AM to 5:30 PM
Calculate hours worked in a standard office day.
→ 8 hours, 30 minutes (8.5 hours)
Overnight Shift: 11:00 PM to 7:00 AM
Calculate duration of an overnight shift crossing midnight.
→ 8 hours (crosses midnight)
Event Duration: 2:45 PM to 6:10 PM
How long does a 2:45 PM to 6:10 PM event last?
→ 3 hours, 25 minutes
Multiple Work Sessions
Three sessions: 9:00–11:30 AM, 1:00–3:45 PM, 4:30–6:00 PM.
→ 2h30 + 2h45 + 1h30 = Total: 6 hours, 45 minutes
Tips
- ✓Use this for freelance billing to track exact hours worked across multiple sessions.
- ✓Pair with the Work Hours Calculator when you also need pay calculations and overtime.
- ✓For time zones: subtract the UTC offset difference first, then calculate duration.
- ✓For legal and contractual hour tracking, log to the nearest minute.
Frequently Asked Questions
How do I calculate time duration?
Enter a start time and an end time. The calculator subtracts the start from the end to give total hours, minutes, and seconds. For example: 9:00 AM to 5:30 PM = 8 hours 30 minutes.
Does it handle overnight durations (spanning midnight)?
Yes. If your end time is earlier than your start time, the calculator assumes the end time is the next day. Example: 10:00 PM to 6:00 AM = 8 hours (overnight shift).
Can I add multiple time intervals together?
Yes. Enter multiple time ranges and the calculator sums them for total duration — useful for freelance hour tracking, exercise logging, or multi-session work tracking.
What is the difference between this and the Work Hours Calculator?
Time Duration Calculator focuses on the duration between times (with support for multiple intervals). Work Hours Calculator adds pay rate calculations, break deductions, and overtime tracking — it is more suited for payroll purposes.
How do I convert a decimal hour to minutes?
Multiply the decimal portion by 60. Example: 2.75 hours = 2 hours + (0.75 × 60) = 2 hours 45 minutes. This calculator shows results in both decimal and hours:minutes:seconds format.
Can I use this for time zone calculations?
This calculator works with local times only — it does not account for time zones. For cross-timezone scheduling, convert both times to the same time zone first, then calculate the duration.