Well, depending on your options, if you've got files like
where n= file create date, most people use the convention that n will be formatted like: YYYYMMDD.
This makes it easy to sort files at the cmd line and is also easy for people to read.
You can then simply search for files whose 'extension' is > desired date.
One option is to use rsync, which will only copy any differences it can find between the src and tgt machines::/directory.
(Will do on the fly compression and can use ssh protocol if reqd).