COMEDY : Father Doesn’t Know Best

Jack Gallagher has finally gotten his sitcom on TV. And he’s up front about why viewers should tune in. “I’m in it,” he explains.

Two years in the making, “Bringing Up Jack” is loosely based on Gallagher’s one-man show, “Letters to Declan.”

“It’s a pretty accurate portrayal. We were shooting for a guy late in life who starts a family after being pretty much set in his ways. I had a kid at 38, thinking I had everything figured out,” the veteran guest of “The Tonight Show” said, but he added that the baby, Declan, now 3 1/2, quickly pricked that illusion.

Fatherhood, though, obviously agrees with Gallagher, who performs his stand-up routine at the Irvine Improv through Sunday. Declan is about to have a baby brother or sister.

“I like the process,” he explained from his Sacramento home. “And this is an offshoot.”

The show, which appears Saturdays on ABC at 8:30 p.m. through July 1, was initially scheduled to air at the end of March and follow the highly rated “Grace Under Fire” on Wednesdays. But for reasons still unclear to Gallagher, the show was scratched, then reassigned to its current time.

“Doing the show was a complete departure from stand-up and the one-man show,” Gallagher said. “You have to be conscious of other actors. There are a thousand things to think about . . . lights, marks, cameras, shadows.

“And then they say to be yourself--act natural, be like you are at home. Well, there aren’t 75 technicians and cameras at home. But the performance still comes down to the jokes and getting the audience to laugh. In stand-up, you do what you have to do and go home.”

Gallagher plays Jack McMahon, a sports talk-show host on Philadelphia radio. He’s a man about town, a ladies’ man in his late 30s and he has life figured out. He meets, marries and impregnates a widow who has two sons.

“He realizes he didn’t know as much as he thought he did.”

Gallagher spent almost two years exclusively on the project, working on each episode five days a week before taping in front of an audience.

Now he submits the show for public approval.

“If something happens, we will get to make more,” he said philosophically. “If not, at least these six [episodes] got on the air. I’ll just go on to the next thing. I’m proud of the work we did.”

Gallagher probably should have said next things. “I had a good time acting and also a good time writing. I’d be open to doing either one of those again. I like stand-up. I like the one-man show. I can do five or six things simultaneously.”

This Saturday, Gallagher will only be doing two things simultaneously. Fans will have a rare choice of how they want him: canned or fresh. At the same time Gallagher steps onto the Improv stage, “Bringing Up Jack” will be airing on ABC.

* Who: Jack Gallagher.

* When: 8:30 tonight, 8:30 and 10:30 p.m. Friday, 8 and 10:30 p.m. Saturday and 8 p.m. Sunday.

* Where: The Improv, 4255 Campus Drive, Irvine.

* Whereabouts: Take the San Diego (405) Freeway to the Jamboree Road exit and head south. Turn left onto Campus Drive. The Improv is in the Irvine Marketplace shopping center.

* Wherewithal: $8 to $10.

* Where to call: (714) 854-5455.