Just finished changing the guest book on the website.
The new on doesn't have any annoying adverts and its still free. This one runs on my own hosted web space, under php and SQL data base.
Transferred all the entries over with out any problem.
(This time I was glad not many people had signed the book yet).
Then I saw they were all posted today.
Found the dates are stored in the SQL database, so have to be changed by editing that. Also they are stored in Unix Time (A 10 digit number that relates to the date and time).
A quick google found on on-line converter, enter the new dates and the guest book was back as it should be.