The Daily Show fill-in host John Oliver bows out after tomorrow night. He’s been covering for Jon Stewart since June 10, while Stewart took time off to direct his first film, Rosewater. Oliver’s been getting great reviews for his guest gig. And though this past Monday he told PBS’ Charlie Rose, “I don’t think it’s going to change my life”, and that his goal had been only “not to destroy that machine” during his brief tenure, it’s been a game changer for Viacom Entertainment Group president Doug Herzog, whose empire includes Comedy Central, and who has learned from the experience that there can be life after Stewart. Not that anyone’s making plans to replace Stewart — but it’s got to be nice to know The Daily Show won’t fall off a cliff should the much-loved host who’s been the face of the franchise since January 1999 ever decide it’s time to move on.

Related: ‘Daily Show’ Sees Slight Rise As John Oliver Takes Over

Compared with the same weeks one year ago, Oliver’s overall audience is down slightly — last year was an election cycle, when The Daily Show becomes Must See TV. Oliver snagged an average of about 1.3 million viewers through last week, versus 1.5 million comparable weeks last summer (Live+Same Day). Among the 18- to 34-year-old viewers the show targets, the decline through last week is even smaller — only about 4,000 viewers. And, Oliver’s Daily Show year–to-year decline is tracking to be smaller than had been Stewart’s last couple weeks of originals, before he headed off to make Rosewater. Viewers clearly were curious to watch the show’s Senior British Correspondent try out Stewart’s chair, and his consistent numbers mean they liked what they saw. That’s a major accomplishment for a Brit replacing a guy who looms so large in the pop culture landscape that he won 44% of the vote in a July 2009 Time magazine poll: “Now that Walter Cronkite has passed on, who is America’s most trusted newscaster?” (Stewart walloped the country’s most-watched evening newscaster, NBC’s Brian Williams, who got 29% of the vote.) For Comedy Central, Oliver’s stint is a big win, generating a lot of viewer and media interest during two tough transitions — Stewart taking a powder, and Stewart returning, which he does on September 3.

“I worked on this show for seven years, like, being a kind of NASCAR pit member, ” Oliver explained to Rose on Monday. “I knew how the engine worked, but I never got to drive it before. And only when you drive it do you realize how fast it goes. … The show is an amazing machine. I’m even more impressed with the whole machine now than I was before.”

Watch Oliver’s Tuesday The Daily Show here:

…and random other Oliver-hosted clips here:

…and here: