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

In-Depth Guide

This calculator provides quick and accurate results for your calculations. Simply enter your values and get instant results.

The calculation uses standard formulas and methods to ensure accuracy. All inputs are validated to prevent errors.

Use this tool to save time and avoid manual calculation errors. Results are displayed clearly for easy interpretation.

Tips & Considerations

  • Double-check your input values before calculating to ensure accurate results.
  • Use the calculator regularly to track changes over time.
  • Compare results with different input values to understand the impact of each variable.
  • Consult a professional for important financial or health decisions.
  • Bookmark this page for quick access whenever you need to calculate.

Frequently Asked Questions

This calculator uses standard formulas and methods to provide accurate results. However, results are estimates and should be verified with a professional for important decisions.
Last updated: May 2026