Time Calculator

Add or subtract time values in days, hours, minutes, and seconds. Calculate a future or past date/time, or evaluate time expressions like "1d 2h 3m + 4h 5s".

Add / SubtractDate & TimeExpressionDays & HoursMinutes & Seconds
Three calculation modes:
Add / Subtract — combine multiple time values.
Date & Time — add/subtract from a specific date and time.
Expression — evaluate expressions like 1d 2h + 4h 5s - 2030s.

Time Add / Subtract

Add or subtract multiple time values (days, hours, minutes, seconds)

Days
Hours
Minutes
Seconds
+/−
=

About the Time Calculator

The Time Calculator provides three ways to work with time values. Unlike decimal arithmetic, time uses a sexagesimal (base-60) system for minutes and seconds, and a base-24 system for hours.

The Add / Subtract mode lets you combine multiple time durations in a grid format. The Date & Time mode calculates a future or past moment by adding or subtracting a duration from a specific starting date and time. The Expression mode evaluates free-form expressions using d, h, m, s units.

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Time Units

  • • 1 day = 24 hours
  • • 1 hour = 60 minutes = 3,600 seconds
  • • 1 minute = 60 seconds
  • • 1 week = 7 days = 168 hours
  • • 1 year ≈ 365.25 days = 8,766 hours

Expression Syntax

  • d — days
  • h — hours
  • m — minutes
  • s — seconds
  • Example:
  • 1d 2h 3m 4s + 4h 5s - 2030s

Frequently Asked Questions

1 minute = 60 seconds. 1 hour = 60 minutes = 3,600 seconds. 1 day = 24 hours = 1,440 minutes = 86,400 seconds. 1 week = 7 days = 168 hours. 1 year ≈ 365.25 days = 8,766 hours (accounting for leap years).