Sam4321, even the Ramban tried to mark the date, with the disclaimer that it is only a guess. The purpose of many of these statements are to boost spirits and to give hope that the Geula is near. Barely anyone takes it as the definite date of when Moshiach is going to come.
This is especially the case for pointing out how our Dor fits the bill of Dor Sheben David Ba. If it weren’t a worthy cause Chazal would not have given us hints. And Chazal do give hints as to when to be ????.