Thirty years

The specified time in the future when we will all have flying cars and personal robot servants

1950:
Darling, do you think they'll ever make flying cars?
I'm sure in about thirty years, we'll have them

1970:
Dude...you ever think cars will fly and stuff?
In thirty years man...i'm seein other stuff flying though. Whoaaaa

1990:
Man, you ever think we're gonna have like...robot servants?

Probably in like...30 years, it'll be wicked.

2010:
Yo dawg you think we gon make robot slaves?

Shit yeah dawg in like thirty years or some shit.

Thirty years war

A war that lasted thirty years

Dumbass: Hey how long did the thirty years war last?
Me: Thirty years, dumbass.