Three date questions in one place
How many days are left until the holiday, how old is a contract, what is the date 90 days after an invoice? This page answers the three questions that come up most: the time between two dates, a date moved forward or back by years, months, weeks and days, and a person’s age with the days to the next birthday. Every card updates as soon as you change a date.
Use the calculator in five steps
- Pick the card for your question. The first one measures a period, the second moves a date, the third works out an age.
- Choose the dates with the date picker or type them as year-month-day. Today fills in the current day.
- Read the result under the fields. A period shows years, months and days, the total number of days, weeks plus days and the working days.
- To count the last day as well, as in a hotel stay or a contract term, switch on Count the end day too.
- In the second card, enter how much to add or subtract and read the new date with its weekday.
How months and days are counted
The tool takes the most whole months that fit between the two dates and then counts the days that are left. A step of a month stops at the end of a short month: 31 January plus one month is 28 or 29 February. That makes 31 January to 1 March one month and one day (two in a leap year). The same rule runs in reverse when the end date is earlier, so the result never depends on the order.
Working days and what they leave out
Working days are Monday to Friday between the two dates, with the end date left out unless you count it. Public holidays are not removed, because they differ by country and region. For a deadline in working days, subtract the holidays that apply to you from the number shown.
Calendar dates, birthdays and privacy
The tool uses calendar days without a time or a time zone, so daylight saving changes cannot shift a result. Someone born on 29 February has the next birthday on 28 February in years without a leap day. Dates are read and calculated in your browser, and nothing is sent anywhere.