The command GNU find is the way to go. For example, to delete all files in the current directory between 1 and 5 august, you can use the following command
find . -maxdepth 1 -type f -newermt 2011-08-01 ! -newermt 2011-08-06 -delete
It is better to execute the command without the -delete action, first, to see the listing of interested files (a good substitute could be -ls that produce an ls-like listing).
Removing the -maxdepth 1 specification will traverse all subdirectories, too.
You can also specify hours, for example