Date Calculator

Doing date maths in your head is surprisingly error-prone. Months have different numbers of days, leap years slip in a 29 February, and the moment holidays and weekends enter the picture you are practically guaranteed to miscount. The Date Calculator takes that off your hands and bundles seven calculation types in one tool, so you have the right view for every date question.

The difference mode counts the days, weeks and months between two dates - handy for contract terms, trip durations or the question of how long ago something was. The add-and-subtract mode shifts a date forward or back by a set number of days, weeks, months or years and tells you instantly where you land.

The centrepiece for anyone with official or legal matters is the deadline calculator. It follows the rules of the German Civil Code: Section 187 sets when a deadline starts, Section 188 when it ends, and Section 193 shifts a deadline end that falls on a Saturday, Sunday or public holiday to the next working day. It is exactly this shift that simple calculators get wrong - and it can decide whether a deadline is met or missed. You choose between an event deadline and a start deadline, plus your federal state so the holidays are right.

On top come the everyday calculation types. The age calculator tells you exactly how old someone is to the day, including days lived. The countdown counts down the days to an event, be it a holiday, a birthday or a submission. The weekday calculator reveals what day a date falls on, and the calendar-week view outputs the CW per ISO 8601.

Public holidays are stored for all 16 federal states, including the movable days around Easter, determined correctly by computing the Easter date. Because holidays in Germany are decided by each state, the choice of state makes the difference - Corpus Christi, for instance, is a holiday in Bavaria but not in Berlin.

Everything runs in your browser, no signup and without any date going to a server. You can copy results to reuse them in an email, a calendar or a form. Fast, free and as reliable as a deadline calculation has to be.