Creating date directory and moving files into that directory

[LEFT]I have list of files named file_username_051208_025233.log. Here 051208 is the date and 025233 is the time.I have to run thousands of files daily.I want to put all the files depending on the date of running into a date directory.Suppose if we run files today they should put into 05:Dec:08 directory. I would be verythankful if anybody suggest me the way to do it.

I did try for sometime,but not worked out for me
date_dir = `date +%d:%b:%y`

mkdir "${date_dir}"
In the starting of itself it scolding me like date_dir command not found
[/LEFT]

look at the space before and after the "=" sign
it should be date_dir=`date +%d:%b:%y`

Why Colons in between %d, %b,%y. It gives output like "05:\Dec:08", If you remove the colons and put the command like this
date_dir=`date+%d%b%y` This will give output like 05Dec08

this will give the required date format:)

> date +"%d:%b:%y"
05:Dec:08