In the series pilot, Michael's jail entrance form held by Bellick shows that the character was born on September 8, 1978 in
Toledo, Ohio[15]. However, the birthdate is inconsistent with the characters' dialogue in later episodes. In "
By the Skin and the Teeth", Michael remarks to Lincoln that their father left them thirty years ago. Since the series is set in the year 2005,
[16] the birth date shown on the prop cannot be considered as
canon. Thus Michael is 27 years old since last episode in Season 3,
Vamonos took place on
June 24 2005. This is according to the expired one week
ultimatum given by "
The Company" to Michael for breaking out
James Whistler. However his age is stated by a character for the first time in "
Five the Hard Way" as 31, meaning all the facts above cannot be canon. It's also stated Michael is born in
1976 in the episode
The Mother Lode, but in
Killing Your Number it's retconned to 1974 but still September 8, which fits better with the series timeline
[17].
http://en.wikipedia.org/wiki/Michael_Scofield