It was ruined, though by the last girl—Number 31, as Barney calls her—gets pregnant, having Barney Stinson's child, Ellie Stinson.
In one of the deleted scenes of Last Forever - Part Two , Barney is at the bar on August 31st of 2019 where he is seen smoking a cigar which then Carl yells at him. Barney tells him that he has had a perfect month but Carl tells him that there are 31 days in August. Barney freaks out and pulls the play that he has one day left to live on a girl, who turns out to be Number 31, the mother of his child. Consequently, this places Ellie's birthday around late May or early June of 2020.
I MILA DE KONING AM IN LOVE WITH BARNEY