They are pre-Ben time, but three years earlier they are in regular island time. They're in the 1960's-70's-ish, which means yes, the Dharma is going on.
Oops-- Juliet says 70's-80's
SOUND barrier! It's a sound barrier!
Ben's flashbacks lied to us apparently, because ben was delivered in by Juliet unless he has a sibling they are introducing. Flashbacks show that Ben was delivered on the side of a road by Horace, and his mother died.