Who is elder in Charlie and Alan?

Question

In the TV series 'Two & a half men',Charlie and Alan are brothers, but there is no indication that who is elder. Even Wikipedia doesn't say anything about this. I have watched only season 1. So may be it is revealed in later seasons. Who is elder?

Answer 1

Quoting from Two and Half Men Wiki, in Season 7, episode 11 - "Warning, It's Dirty"

Evelyn reminds Charlie how forty years earlier, he had asked for a little brother for Christmas, which in contrast puts in doubt whether Alan was unplanned or not.

IMO, this proves that Charlie was the elder brother.

Answer 2

Charlie is the older brother. There are jokes in a number of episodes that establish this.

Also, the Two and a Half Men wiki does confirm this:
Dr. Alan Jerome "Al" Harper, DC, is a character from the CBS sitcom Two and a Half Men. Portrayed by Jon Cryer, Alan is the hapless and helpless biological father of Jake Harper, roommate and best friend of Walden Schmidt and the surviving younger brother of Charlie Harper.

The wiki lists the years of birth: Charlie: 1967, Alan: 1969.