retrieve the file.

How will retrieve for a particular months file in UNIX say for example from January to February 2008.

File by Unix filesystem timestamp or by date in it's filename?

In the 1st case, use

man find

and have a closer look at the -mtime switch maybe, also conjunction of -a for "and".

In the 2nd case, use something like

find .| grep -i <entersomepatternhereaccordingtoyourdateinthefilename>