I was looking for some library to handle calendar events. Something PIM-
style, something useful, that could check if, for example, 2 weekly 
repeated events that start on Monday morning and last until December 
conflict with each other.

Then I found 'calendar' module in the standard library.

My question: how this thing ever made it to the standard library?

Maybe it was useful back in the days, if somebody could not get BSD or 
GNU sources for cal(1) . Nowadays, even if it is able to print HTML 
calendars, lets face it - who will use that functionality? You can 
easily find HTML calendars with a lot of JavaScript support, that can be 
customised in a thousands of ways.

I suggest we delete this module completly.