Date & Time Tools

Date Calculator

Calculate the exact number of days between two dates, or find a future/past date by adding or subtracting days, weeks, months, or years. Handles leap years, working days, and calendar months correctly.

Instant date calculations Handles leap years & DST Browser-only — works offline

Features

  • Calculate days, weeks, months, years between two dates
  • Add or subtract any number of days/weeks/months/years from a date
  • Business days mode — excludes weekends
  • Includes or excludes the end date
  • Shows result in multiple units (days, weeks, months, years)
  • Handles leap years and variable month lengths
  • No account, browser-only

How to use it

  1. Choose mode: 'Between two dates' or 'Add/subtract from date'.
  2. Enter your date(s) using the date picker or keyboard.
  3. Results appear instantly — days, weeks, and months.
  4. Toggle 'Business days only' to exclude weekends.

Use cases

  • Calculating project deadlines and durations
  • Finding how many days until an event
  • Checking contract expiry dates
  • Calculating notice periods for employment or rental

Limitations

  • Browser processing depends on available device memory for very large inputs.
  • Tool-specific limits based on file format or browser support are noted on each tool page.
See also

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Questions & answers

Frequently asked

Does the calculator count the start date?

By default, the duration is calculated exclusive of the start date (e.g. Jan 1 to Jan 31 = 30 days). Toggle 'Include start date' to get 31.

How does business day mode work?

It excludes Saturdays and Sundays. Public holidays are not excluded as they vary by country.