When Smeagol was born are not known but he was born into a clan of the Stoors East of Hithaeglir in the vales of Anduin. His friend Déagol found the One Ring in Anduin about the year T.A.2463. I do not think it would be unfair to believe Smeagol and Dèagol were young Hobbits not full grown at that time. Hobbits were regarded adults when they reached the age of 33 years so to place Smeagol`s birth as estimated in T.A. 2437 seems reasonable of several reasons. Seven years after Smeagol had acguired the ring ( 2470 ) he hides himself benieth Hithaeglir and this might be the same year as that were he was dismissed / thrown out of his family for good and the same year he came to full manhood ( 33 years old ) That would place his birth in 2470 - 33 = 2437.
Tout repose évidemment sur le fait, comme chez Foster, que Smeagol serait de la même espèce que les Hobbits et que l'âge de la majorité (33) serait le même.
A la décharge de Foster, Sméagol réclame l'anneau comme cadeau d'anniversaire...
Didier.