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

Runs entirely in your browser — no data is sent to a server

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.