If you only need to compress files made/modified AFTER a certain date,
you can try SyncBack:
http://www.2brightsparks.com/syncback/
1. Make a profile with the source and destination directories.
2. In Expert mode | Compare Options, set a number in "Ignore files that
have not been modified/created within the last x days".
3. Then, in Compression, select "Compress the files in the destination
into Zip files".
Before proceeding, you can run a simulation of the Profile, and sort by
date the files to be zipped, to see if you calculated the number of days
correctly.
HTH,
Demetris