His last credited (https://www.imdb.com/name/nm0790585/) on screen role was in 2003, which is now almost 20 years ago. Doug is now (https://helenair.com/entertainment/hollywood-perspective/article_cfd89194-441e-59a1-86b2-4fa8ec7d8087.html) 72 years old, so it's probably too late for a comeback. Post-Day by Day (https://www.datalounge.com/thread/15612442-day-by-day), his most notable acting roles (https://www.datalounge.com/thread/15731555-cheesiest-sitcom-ever) were probably that as Cher's father (http://www.tellytalk.net/threads/douglas-sheehan-and-joan-van-ark.8926/post-221216) on the TV adaptation of Clueless (when the show moved from ABC to UPN) and as Sabrina's father on Sabrina the Teenage Witch.

He was also on Knots Landing playing Ben Gibson. I liked him in that role.

Based on articles like Musical ‘clash of past and present (https://helenair.com/entertainment/yourtime/musical-clash-of-past-and-present/article_8b5f932e-1299-11e2-81e9-0019bb2963f4.html) and A new twist on an old classic (https://www.thesheridanpress.com/news/local/a-new-twist-on-an-old-classic/article_1a30ba49-ba2e-58cc-938a-dafcd98f975a.html), it appears he left Hollywood (https://www.sandiegouniontribune.com/sdut-san-diego-raised-actor-premieres-rapunzel-musical-2005may25-story.html) and moved to Wyoming, where he’s been writing and directing stage plays and runs a theatre company in Big Horn.