I wanted a calendar, with a month per sheet of paper. This module provided one quickly and easily.
I first looked to buy a suitable calendar, and then tried searching for an OpenOffice template for printing my own, both without success. I was about to resort to writing a program to print my own when I found PostScript::Calendar, which saved the effort The example program which comes with the module was an excellent template, and only required minor tweaking to get the output I wanted.
There are a few caveats (see AnnoCpan), but if you want to create month-per-sheet calendars this module has already done most of the work for you.