". . . If man is still alive. . . "

What sounds like describing the distant future is already history for some of us. Or even furter away than 500 years. The Gregorian calendar has become the standard calendar for worldwide communication but it is by large not the only one. And often people are using more than one calendaring system on a daily basis because their local calendar is something completely different. So when you aim for international applications you wshould know the quirks and odds of different ways of keeping track of days and months and years. And if only to decide to not use them ;-)

In this session we will have a look at what makes a calendar, what kind of calendars there are, where and how they are used. Besides that we'll check how (or whether at all) we can move a date from one system to the other and what options we have to handle that mess in our programming language.