That looks correct. Though, there might be better options.
See How do I transfer new/modified files only?

I'm using the synchronise function currently to sync to a local file store from an FTP server, due to the nature of the files being download I need to remove these from the local file store when they have been moved on by another process.

If I use the synchonize function it's going to replicate the files that have been deleted locally by the other process.

I've been reading on the filemask and my plan is to run the synchronise every hour and pick up the previous hours files only.

For example run the script at 9:15 and pick up everything between 8:00 and 9:00

I think I have the filemask timestamp correct but I could do with just a confirmation before I make the changes.

Would this work?