Thank you Carol
Thomas and Mary Day's daughter Hester was my great great grandmother.
If John was born in 1837 maybe they were married around there.. given they did not have children before which did not survive the census.....
I have also seen bedfordshire, but on ancestry.co.uk census 1851 showing Thomas, Mary, John, Joab and Hester, shows him as Cambridgeshire and I found a Thomas Day of that date from Wisbech, but not sure.
Thanks for your help with this
Sara