Time Calculator

Add or subtract times, compute a date after a duration, and evaluate time expressions.

Time Calculator

Add or subtract two time values. Enter days, hours, minutes, and/or seconds. Blank fields default to 0.

Day
Hour
Minute
Second

Add or Subtract Time from a Date

Select a start date and time, then add or subtract a duration to find the result.

Start Date & Time
Duration to Add / Subtract
Day
Hour
Minute
Second

Time Calculator in Expression

Type a time expression using d (days), h (hours), m (minutes), s (seconds) with + or − operators. Spaces are optional.

Examples:
1d 2h 3m 4s + 4h 5s - 2030s + 28h
3h 45m - 1h 20m 30s
7d + 12h - 4h 30m

Add, subtract, or find the duration between times with our free time calculator, handling hours, minutes, and seconds with automatic carrying across units.

How Time Calculations Work

Time values are converted to total seconds for calculation, then converted back to hours:minutes:seconds format, properly carrying over when minutes or seconds exceed 60.

How to Use This Calculator

  1. Select operation (add, subtract, or find duration)
  2. Enter your time values in hours:minutes:seconds
  3. Click Calculate to see the result

Frequently Asked Questions

Does this handle times crossing midnight?

Yes, duration calculations account for times that span across midnight into the next day.

Can I add multiple time values at once?

Some versions support adding several time entries together; check if your calculator has multiple input rows.

What's the difference between this and the Hours Calculator?

This tool handles general time arithmetic; the Hours Calculator specifically focuses on work-hour tracking and timesheets.

Does this convert between time formats?

This calculator focuses on arithmetic; for format conversion (12-hour vs 24-hour), check your input settings.