How to revert modified dates/times to original dates/times

I have a backup folder with a hundred or so files each of which have the correct modified date/times. Each file in the current folder was updated globally causing all files to have the same date/time. Is there a way to update the current modified dates/times using the backup file date/times?

You will need a newer version than Opus 10, but either of these two script add-ins can be used to copy timestamps from one set of files to another:

At least with ClipAttr (I wrote that one; I'm less familiar with ClipboardEx), the file names will be ignored. It will copy the timestamp from the first file in one side to the first file on the other side, and so on.

So you will need to make sure the same files are in both folders, and deselect any files which are only in one folder or the other. (You can use commands in Edit > Select Other... to do that, at least in Opus 11 and 12. I'm not sure the menu items were there by default in Opus 10, but you'll need a newer version to use the scripts anyway.)

ClipAttr always copies both modified and created timestamps. ClipboardEx lets you copy either or both.

Yep, using ClipboardEx is basically the same for the selection based copying and pasting of timestamps.
Commands read like this if you only want to copy the modified timestamps:

To be run on the items carrying the correct modified date/time.

To be run on the items with the modified date/time to be corrected.
ClipboardEx PASTETIMESTAMPS=modified

As Leo mentioned, you should make sure to have the same items and the same number of items selected during this process. If not you may end up with an unpredictable pattern of how the dates are being applied to the items.

Thanks to everyone, especially Leo for help with my problem. It's now been resolved.