Time Calculator
Add or subtract time durations, or calculate elapsed time between two clock times.
How this is calculated
Elapsed = end − start (handles midnight crossover). Add/subtract adjusts clock time by the given duration.
Frequently Asked Questions About Time Calculator
A time calculator computes elapsed time between two clock times, or adds and subtracts time durations. It handles midnight crossovers and converts between hours, minutes, and seconds.
How do I calculate elapsed time between two times?
Enter start and end times (e.g., 09:00 AM to 5:30 PM) and the calculator shows the duration. If the end time is before the start time, it assumes the next day and accounts for midnight. For example, 11 PM to 2 AM = 3 hours.
How do I add or subtract time?
Select "Add time" or "Subtract time" mode, enter the hours/minutes/seconds to add or subtract, and enter a starting time. For example, starting at 2:30 PM, add 1 hour 45 minutes = 4:15 PM.
What is total seconds used for?
Total seconds converts your duration into a single number. Useful for payroll calculations, billing, scientific work, or database storage. For example, 1 hour 30 minutes = 5,400 seconds.
Does this calculator handle overnight shifts?
Yes, if you work a shift like 10 PM to 6 AM, enter the times and it calculates 8 hours correctly. It accounts for the midnight crossover automatically.
Can I use 24-hour time format?
Yes, enter times in 24-hour format (14:30 for 2:30 PM, 23:45 for 11:45 PM). The calculator works with both 12-hour and 24-hour formats as long as you're consistent.
How accurate is the time calculation?
Accuracy depends on your input. Seconds are calculated precisely. If working with large time spans (days or weeks), you may want to use a date calculator instead to ensure accuracy across multiple days.