How can I change the format of a date from the command line?

Question

What\'s the quickest way to convert a date in one format, say

2008-06-01

to a date in another format, say

Answer 1

Reading the date(1) manpage would have revealed:

-j   Do not try to set the date.  This allows you to use the -f flag
     in addition to the + option to convert one date format to another.