I needed a way to convert the contents of the %DATE% variable (which looks like: Thu 01/22/2009) into mmddyy format. The windows SET command can do this.
So, let's disect it by looking at a smaller portion first. (Remember that Windows command shell variables are reference as No value assigned. When you use the Set command, the variable name can have modifiers)
%DATE% is the variable we are searching.
%DATE:~4 says to start at offset of four from the beginning of the string
,2% says return two characters.
Set Shortdate=%DATE:~4,2% echo %Shortdate%
Would print: 01 (assuming it is January in the US)
So we could string this mechanism together like this
Set Shortdate=%DATE:~4,2% Set shortdate=%shortdate%%DATE:~7,2% Set shortdate=%shortdate%%DATE:~12,2%
or really shorten the process as shown in the first example