Hi Barbara Boram it is fancy internet BS, no one will answer your question because no one knows they all just copy and paste
I posted this about this a over a year ago but no one cares, welcome to the New Amsterdam tree! (and yes i know you've been here for years ;)) https://www.geni.com/discussions/173064?msg=1179626
Eugene, the link you posted makes this Jan Gerritse Decker part of a Broersen family, many trees link Jan Gerritse Decker to Jan Broer Decker but there is simply no evidence of any link prior to their children marrying.
Both Jan's apparently died in Port Jervis in 1717 which I call BS on too but i can't find any evidence to prove either of the died there nor which one died in 1717 so i have left the data in both profiles because there is a good chance it is wrong for both me.
As far as supporting evidence of his DOB/place goes, nothing short of a family bible or his will is going to answer the question.
The Gelders archief is readily available but his baptism does not appear in it, so either he was never baptised or the date is wrong or there is another Heerde somewhere else in the world (not in Gelderland).