Backup only if changed

hello all,

First time on here. I have a Filemaker 16 solution on a file server which contains 12 files. I am the only one who uses the database which is why it is not on Filemaker server. I have scheduled it so it creates a backup when I close the database. I have a global field that is set with a timestamp when it backs up and the backup script checks that timestamp and only backs it up if that timestamp is more than 3 hours. The issue is that it takes a bit of time to back up the 12 files. Most of these files are relatively static. Suppliers, Job codes, etc. 

When I back up the files I replace the extisting backups so there is only the one set. I would like to be able to check each file and if there has been no change, it doesn't back it up. I am not sure how to do this without creating a monitor for each field to see if it has changed. Is there a quicker easier way to accomplish this?

Thanks in advance for any help you can give.

Mike