mbdrazin wrote:
since LR4 has the right dates still can i re-save metadata to file for all photos and then reimport in LR5 to straighen this out?
If all the files have been "moved" rather than "copied", then I don't think you'll be able to do that as all the files in the LR4 catalog will be missing.
So, with no backups of your images, then I think your only option (assuming you don't want to accept the current situation) would be to change the capture date using the Metadata>Edit Capture Time command (you can use this on multiple selected images if you can identify same day shots), then create the correct dated sub-folders within Lightroom and drag and drop the images into their correct sub-folder.
I'm still curious to understand how this has happened, as I find it difficult to see how Lightroom could/would remove the EXIF date information during an Import with Move process. Would it be possible to identify the SAME image (one without the date in LR5) in both the LR4 and LR5 catalogs, change the Metadata panel view from "Default" to "EXIF and IPTC" then take screenshots of both?