Rails - MySQL UNIX Timestap issue

Apologies if this has been posted before but I’m all googled out
looking for a solution to this!

I have a database that contains a number of pre-1970 dates which seems
to be causing a update error in Rails when I try to update to MySQL. I
assume that this is to do with the UNIX timestamping issue.

Question is, which part of the process is causing the issue and how do
I get around it. I’d rather not convert the date to a string if

Thanks in advance