How to use Calendar to view significant dates in history

Fancy knowing what’s happened today in history but have no internet connection? Or just REALLY bored at work and fancy reading some interesting facts?!
Well don’t you worry, your Mac OS X system has a built-in calendar history of events for you. While they are mostly US events in history, but it still makes an interesting read. This isn’t new to 10.8, in fact it’s been hidden in your system for quite some time!
Step 1. Open a terminal window. (/Applications/Utilities/Terminal)
Step 2. Enter the following exactly as printed, (copy and paste if possible!):

cat /usr/share/calendar/calendar.history

Step 3. Sit back and enjoy reading a list of significant dates in history!
view calendars significant dates in history
You can tweak the calendar history a little, for example entering:

cat /usr/share/calendar/

will display dates in history relating to music,

cat /usr/share/calendar/calendar.birthday

displays a list of famous births and deaths.
Perhaps more relevant, would be:

cat /usr/share/calendar/

to find out important dates in history in the computer world.
You can also use the grep command to filter through the results. To find out what happened in musical history on 27th November, I would use the following :

cat /usr/share/calendar/ | grep 11/27

grep command view music history
Or to find out when Apple was incorporated in the state of California

 cat /usr/share/calendar/ | grep Apple