Terminal Tips: What Day of the Year Is It?

This is a rather silly tip to impress (or freak out) your friends by making them think you are mildly autistic /
weird.  Simply launch the Terminal (found in /Applications/Utilities/) and type cal -j and hit return. This will display a calendar of the current month listing the julian dates (days numbered in sequence from January 1st).  Today, for example, is the 85th day of the year. Now plotting which day in the julian calendar corresponds to which regular date can be difficult (if you didn't know that today was the last Saturday in March, for example), so simply type cal and return in the Terminal to list a regular calendar.

You can also type cal -y to list a calendar for the entire year and cal -jy to list the julian calendar for the entire year, so you can pull out odd facts, such as "April Fools Day is the 91st day of this year; it varies on leap years."