Calculate how many days are between two dates. Along with the total days, it shows weeks + days, a years/months/days breakdown and the number of business days (weekdays only, as a rough guide). Turn on "count both endpoints" to count the start and end date as a full day each — the way event durations are counted. A second mode adds or subtracts a number of days, weeks, months or years from a base date and shows the resulting date, its weekday and the total day offset. Month and year additions clamp to the end of the month (Jan 31 + 1 month = end of February). Everything runs in your browser; the dates you enter are never stored or uploaded.

How to use

  1. In "Difference", enter the From and To dates (To defaults to today).
  2. Read the total days, weeks + days, years/months/days and business days. Tick "count both endpoints" for inclusive counting.
  3. In "Add / subtract", pick a base date, an amount (days/weeks/months/years) and before/after to get the resulting date.

FAQ

How are business days counted?

Business days count weekdays only (Monday to Friday), excluding Saturday and Sunday. Public holidays and company-specific closures are not included, so treat the figure as a rough guide.

What does "count both endpoints" mean?

It chooses whether the start and end date are each counted as a day. For example, the 3rd to the 5th is normally 2 days, but with both endpoints counted it is 3 days — the way event durations are counted.

What is one month after January 31?

February has no 31st, so the result clamps to the end of February (28th, or 29th in a leap year). Year additions clamp to the month end the same way.

Are the dates I enter stored?

No. All calculation runs in your browser; the dates are never stored or uploaded and are not sent to any server.