I have a large number of files in a folder each with the date as the filename.
20130101 20130102 20130103 . . . 20130131
similarly for other months 20130201 to 20130230, the pattern is [Year][Month][Day].
I need to make a tar file of the first fifteen files from JAN to APRIL
2013[01-04][01-15]), since double digit number range is not allowed in
grep. How should I search this pattern?