Date & Age Calculator

Work out the days between two dates, your exact age in years, months and days, the number of working days in a period, or the date a given number of days from now.

Date & Age Calculator

Work out the days between two dates, your exact age in years, months and days, the number of working days in a period, or the date a given number of days from now.

Calendar arithmetic here respects real month lengths and leap years — a month is not treated as 30 days.

How to read the result

  • The difference is counted in whole days between the two dates. Whether the last day "counts" depends on your contract, so check the wording before you rely on the number.
  • Working days count Monday to Friday and nothing else. Public holidays vary by country and are not deducted — subtract them yourself for the country in question.
  • Adding months lands on the same day number where it exists: 31 January plus one month gives 3 March in a normal year, because February has no 31st. That is how spreadsheets differ from each other, and why the result is worth checking.
Date & Age Calculator

Frequently asked questions

How do I calculate the number of days between two dates?

Pick both dates and the tool counts the whole days between them, taking leap years into account. The question that catches people out is whether the final day counts: a notice period "of 30 days" starting on the 1st may end on the 30th or the 31st depending on the wording, and the two readings are a full day apart. Count the days with the tool, then read the contract to see which convention it uses. For anything legal or financial, the convention is written down somewhere and it is worth finding rather than assuming.

How is exact age calculated in years, months and days?

By subtracting the calendar parts and borrowing where necessary, exactly as you would do by hand — not by dividing the total days by 365.25. That distinction matters: division gives an age that drifts by a day or so depending on how many leap years you happened to live through, while calendar subtraction gives the age everybody agrees on. Someone born on 29 February is a genuine edge case; most legal systems treat their birthday as 1 March in a non-leap year, and this tool moves the next birthday accordingly.

Why does my working-day count differ from my colleague's?

Almost always because of public holidays, occasionally because of the first and last day. This tool counts Monday to Friday between your two dates and deliberately does not deduct holidays: they differ by country, by region within a country and by year, and a tool that quietly applied one country's calendar to everyone would be wrong more often than it was right. Take the number here and subtract the holidays that actually apply where the work is being done. Half-day rules, if your organisation has them, are a separate conversation.

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