Time Duration Calculator

Calculate the hours, minutes, and seconds between two times.

Start Time ()
End Time ()
 

Results are for reference only.

How Time Duration Calculation Works

This tool calculates the time difference between two given times by first converting both into 24-hour format for consistency, then breaking each down into total seconds since midnight (hours × 3600 + minutes × 60 + seconds).

It subtracts the start time's seconds from the end time's to get the raw difference in seconds. If the result is negative (indicating an overnight duration), it adds 86,400 seconds (24 hours) to correct it.

Finally, it converts the total seconds back into hours (dividing by 3,600), minutes (remainder divided by 60), and seconds (final remainder), giving the duration in an easy-to-read HH:MM:SS format along with separate hour/minute/second breakdowns.

The calculation handles AM/PM times automatically and works for any same-day or overnight duration.

Step 1: Convert to 24-Hour Format

The calculator first converts both times to 24-hour format for consistent calculation.

9:30:40 AM → 09:30:40
6:40:55 PM → 18:40:55 (PM = +12 hours)
Step 2: Convert to Total Seconds

Each time is converted to total seconds since midnight using the formula:

Total Seconds = (Hours × 3600) + (Minutes × 60) + Seconds

Start Time (9:30:40 AM):
(9 × 3600) + (30 × 60) + 40 = 34,240 seconds

End Time (6:40:55 PM):
(18 × 3600) + (40 × 60) + 55 = 67,255 seconds
Step 3: Calculate Difference in Seconds

Subtract start time from end time:

67,255 (End) - 34,240 (Start) = 33,015 seconds

If result is negative (overnight duration), add 86,400 seconds (24 hours)

Step 4: Convert Back to Hours, Minutes, Seconds

Break down the total seconds:

Hours: 33,015 ÷ 3,600 = 9 hours (32,400 seconds)
Remaining: 33,015 - 32,400 = 615 seconds

Minutes: 615 ÷ 60 = 10 minutes (600 seconds)
Seconds: 615 - 600 = 15 seconds
Final Result

The duration is presented in multiple formats:

Digital Format: 09:10:15 (HH:MM:SS)
Readable Format: 9 hours, 10 minutes, and 15 seconds
Alternative Formats:
- 9.17 hours
- 550 minutes
- 33,015 seconds
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