Online Time Calculator
🔢 Dual Modes – Add/subtract time durations or calculate differences between two times.
⏰ Save Effort – No mental math or manual counting—get instant, accurate results.
📱 Always Works – Mobile-friendly and works offline after loading.
💡 For Everyone – Perfect for work, billing, fitness, cooking, and scheduling.
Try it now—save time while calculating time!
This mode allows you to:
Add hours, minutes, and seconds to a starting time
Subtract hours, minutes, and seconds from a starting time
Calculation Process:
The calculator converts the starting time to total seconds
Converts the duration (hours, minutes, seconds) to total seconds
Performs addition or subtraction operation
Converts the result back to HH:MM:SS format
Handles overflow (times crossing midnight) automatically
Example 1: Adding Time
Start Time: 14:30
Operation: Add Duration: 3 hours, 45 minutes Result: 18:15
Example 2: Subtracting Time (Crossing Midnight)
Start Time: 08:00 Operation: Subtract Duration: 10 hours Result: 22:00 (previous day)
This mode calculates the duration between two times, always showing the shortest possible duration.
Calculation Process:
Converts both times to total seconds
Calculates absolute difference
If difference > 12 hours, shows 24 hours – difference (shorter duration)
Converts back to HH:MM:SS format
Example 1: Standard Difference
First Time: 09:00 Second Time: 13:30 Difference: 04:30
Example 2: Difference Crossing Midnight (Shows Shorter Duration)
First Time: 23:00 Second Time: 01:00 Difference: 02:00 (not 22:00)