My Passport for Mac dated 01 January 1970

I have backed up my files from my old Macbook, and have been planning on transferring them to my newer iMac. When I have come to access the files they are all showing ‘greyed out’, and inaccessible. They all have a size of zero bytes, and a date modified of 24 January 1984. When I look at My Passport in general, it has a date created of 01 Jan 1970 (please see screen shot attached).

I have checked my time and date settings on both the macbook and my iMac, which are correct, does anyone know how to fix this?

Any other details needed please just ask.

Many thanks in advance,
Sara