Using a most excellent tool from (den4b called Renamer)  - one of the few tools I happily purchased and want to promote it!   The regular expression to rearrange the date (helpful for date-stamping files) is:   (.*)([0-9]{4}[-_]{0,1}[0-1][0-9][-_]{0,1}[0-3][0-9])[-_]{0,1}([0-2][[0-9][0-5][0-9][a,p]{0,1}){0,1}[-]{0,1}(.*)  ---1-----------------------------------------------2_________-------------------------------------3________----4   then it can be easily reordered:  $2-$3-$1-$4   For those of you unfamiliar with REGEX or ReGularEXpressions- it breaks down like this:     (.*)   =   $1   will match zero or more of any characters  By enclosing it in parenthesis () it becomes a sub expression.   Since it is the first subexpression it can be referenced to be reordered with $1 in Renamer.   (   =  left parenthesis start of the second expression   $2   for the year-month-day   left parenthesis is the the start of the next expression to Capture. If the ...