Backup files show incorrect date

I just completed a backup using Ghost 15.0, using a WD My Book Live network drive. The drive had been powered off for about 4 weeks before I plugged it in and did the backup. The file date on the image file Ghost created is wrong by over a month. Could this be a bug in Ghost, or more likely a bad BIOS battery in the network drive's internal computer?

Copy a file to the network drive and see what the date says.

Thanks Dave. The drive's internal date was indeed the problem. All fixed now.

Pete