[codydkdc]

how long is an age?

[amelius]

We're living in the information age. Not sure when or what the next age will be, but you get the idea.

[arijun]

Pretty sure we’ve already made it to the disinformation age.

[GuinansEyebrows]

in the tolkien legendarium they may be over 3000 years.

[tough]

a year (probably)?

[drewcoo]

An age is a long amount of time.

"An age" is probably an attempted cleaning-up of "a coon's age."

https://grammarist.com/usage/coons-age/