Mass Effect Trivia #4:

Commander Shepard has a canonical birthday.

Commander Shepard’s canon date of birth is April 11th, 2154 CE. This means that Shepard is younger than Kaidan Alenko (born in 2151), Miranda Lawson (born in 2150), Thane Krios (born in 2146), Kahlee Sanders (born in 2139), and Saren Arterius (born in 2139). This would make him/her only three years old at the start of the First Contact War in 2157, 29 years old at the start of Mass Effect, and 31 years old during the events of Mass Effect 2 (after (s)he is revived by the Lazarus Project, of course).