Date calculator

How the end of a month is handled

Add a month to 31 January and you get 31 February, which does not exist. In that case the calculator takes the last day of the month: 28 February, or the 29th in a leap year, and says so under the result. Recurring reminders in KIPRI behave the same way.

Working days without public holidays

Working days here are Monday to Friday. Public holidays and moved days are not taken into account: they differ between countries and change every year. For deadlines where every day matters, check your country's official calendar.

The first and the last day

Between the 1st and the 10th there are nine days if you count the gaps, and ten if you count both days inclusively. For a holiday or a course of treatment you usually want the second, which is what the "Count the last day too" box is for.

What date will it be in N days

Counted from 5 November 2026. A row opens that span in the calculator, where you can change the starting day and the number of days.

How many days until a birthday

Open the "How long until" tab and set the date of the next birthday. The calculator shows what is left in days and weeks and names the weekday it falls on. With several dates the birthday calendar is handier: it keeps the whole list and works out the days left for each one.

Birthday calendar

When you need a reminder, not just a date

If you need the date so as not to miss something, a calendar file is the minimum. In KIPRI the same reminder can repeat every month or year, with a heads-up beforehand and quiet hours.

How reminders work in KIPRI