Daria Day was a series of Season 1 repeats in advance of "Arts 'N Crass" airing February 16, 1998 - briefly interrupted by Road Rules.
Off-canon canon Daria and Jane gave intros to each episode and responded to readers' letters, even the creepy ones. And there were quite a few!
During this, Daria and Jane gave the ages of Daria, Quinn, and Trent (16, 14 and a half, and 21 respectively).
Daria and Jane also hosted a Daria Day in advance of the 3rd season premiere in 1999, but no transcript or screen capture is known.
Transcript at Outpost Daria Reborn