... but why does this article state that Batman's birthday is in 1972, when he first appeared in comic form in Detective Comics in May, 1939 (according to Wikipedia)? Am I missing something?

It's talking about his in-universe birthday.

There is afaik no real canon source for the birth years that are listed here at comic vine for the Batfamily members, and if you comepate them they anyway don't realy match.

Btw. the original golden age Batman was conically retconned to be born in 1915 (America vs. the JSA #1). And if you go by the old comics his birthday is actually the 7th of April (World's Finest #33, Star-Spangled Comics #91).

@ejjackson: Well DC had multipole eras, each happening on different universes, each with their own history and timelines:

• golden age
• silver age
• modern age
• new 52
• rebirth

Ah, thanks everyone, that makes sense!

new 52 and rebirth are still the same earth, even if the after the end of reborh the time line might change, but that also happened during the modern era on different occasions due to he different crisises.

Why does everyone forget to mention the Bronze Age?

Because Silver and Bronze Age are set in the same continuity.

Batman's bday is everyday.

Never argue this.

After the 60's fun comics, comics started to get more serious and darker. So the this shift in style in the 70's is sometimes called the Bronze Age. But it is in no way a reboot or a change in the current continuity.

Oh I always thought silver age Bats and Bronze Age Bats were two different versions of Batman

They are the same, and the Golden age comics are (for the most part) technically also still canon for the silver/bronze age Batman (even if the golden age Batman exists as a different character on a other Earth) since there was never a clear reboot or break in the Batman comics until Crisis on infinite Earth.