Uttir

Date Calculator

Count the days between two dates, or add and subtract days from any date.

Date Calculator — Two date utilities in one: the gap between any two dates (in days, with week/month/year equivalents), and a date shifter that adds or subtracts a number of days — useful for deadlines, due dates, and countdowns.

Date math runs locally in your browser.

What is date calculator?

Two date utilities in one: the gap between any two dates (in days, with week/month/year equivalents), and a date shifter that adds or subtracts a number of days — useful for deadlines, due dates, and countdowns.

All math respects real calendar dates, including month lengths and leap years, and uses your local timezone so a date you pick is the date you mean.

How to use it

  1. Difference

    Pick From and To dates to see the gap in days and equivalents.

  2. Shift a date

    Pick a starting date and a day offset; negative values go backwards.

Examples

January gap

From 1 Jan to 31 Jan.

2026-01-01 → 2026-01-31

Result: 30 days

Due date

30 days after 30 Jan 2026 crosses the month boundary.

2026-01-30 + 5

Result: Wed, Feb 4, 2026

Frequently asked questions

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