One thing that never ceases to amaze me since switching to Linux at home is how useful and efficient the command line can be. The 'cal' command is another great example of this. (Also note that the cal command works in Cygwin too, provided you've installed the util-linux package.)
If you need a quick glance at the calendar for the current month, just type 'cal' at the command line and you get a neat little calendar highlighting the current day as shown below:
But say you want to see the calendar for a future or past month. Again, very efficiently you just type 'cal mm yyyy' where xx is the month and yyyy is the year. Just like this:
Also useful is the -y switch which will display a complete calendar for the current year:
And of course you can see the complete calendar for any year you want by preceding the -y switch with the year itself like so:
So there you have it. A little useful tip for displaying calendars at the Linux (or Cygwin) command line. There are of course many other options. So check out the man page for the cal utility by typing: 'man cal' and tinker away!