Robocopy – Overwrite all files unless file in destination is newer

The title pretty much sums it up.

I had restored a file share recently from a backup. Come to find out after about a day of users in production we started to notice some files were corrupt. Pulling those files from the backup again shows that the backups are in fact intact. However, users are modifying files going forward.

Using robocopy, can I overwrite all files in this share skipping newer files on the destination? In other words, I basically want to recopy everything unless the user has made changes to a file on the share.

The /is flag seems intriguing, but unsure if it will overwrite a file with a newer timestamp.

And insight would be greatly appreciated.