''It's About Time'' (1966-67) was about two astronauts who, after breaking the speed of light, accidentally travel back in time to prehistoric Earth. Unable to return, they make friends with the "natives" in the stone age. An attempt to do a live-action version of ''WesternAnimation/TheFlintstones''.

Halfway through the season, having run out of stone-age jokes, the show was {{retool}}ed by having the astronauts manage to fix their spacecraft and return, bringing some of the stone-age characters with them, turning the show into a FishOutOfWater about stone-age characters trying to figure out modern life. This wasn't very successful either, and the show only lasted the one season.
* OneMillionBC: The astronauts accidently break the time barrier and get stranded in One Million B.C.
* AnimatedCreditsOpening: Revamped with its plot points reversed after the {{Retool}}.
* BlazingInfernoHellfireSauce: In "Stone Age Diplomats", the food that Shad and Gronk prepare for the astronauts and the "Ambassador of Nordania". It's a mixture of everything with a generous helping of hot sauces mixed in. Naturally, the astronauts, the ambassador and the landlord choke or gulp down water. Shad and Gronk love it.
* ComicBookAdaptation: One issue long.
* ContemporaryCaveman
* EverytownAmerica: Riverview, Ohio; Lt. Hector Canfield's oft-mentioned hometown.
* ExpositoryThemeTune
* FantasticComedy
* FishOutOfTemporalWater
* FishOutOfWater
* GettingCrapPastTheRadar: In the pilot the female Cave Dweller was named Shag. The radar then got fixed for the series in which her name became Shad.
* HalfHourComedy
* MachineWorship: In ''School Days, School Days'', Shad and Gronk give a sacrifice to the garbage disposal calling it the "god of Garbage"! At the end of the episode, after Mac and Hector enroll them in night school to catch up on a million years of civilization, Gronk mentions they're going to be taught about Edison, god of the Electric light.
* MyLifeFlashedBeforeMyEyes: In "Androcles and Clon", it was said by both astronauts after a narrow escape with being clubbed and pushed off a cliff by Clon.
* NubileSavage: Cavegirl Mlor, the daughter of Shad and Gronk. She's a beautiful teenaged blond, dressed in animal furs. This is in spite of living in a cave in a million B.C, amongst a very primitive tribe. Astronauts Mac and Hec were both instantly smitten when they first met her in "And Then I Said Happy Birthday To You".
* PropRecycling: Creator/SherwoodSchwartz reused the ''Series/GilligansIsland'' lagoon and the spacecraft used in one ''GI'' episode.
* Creator/SherwoodSchwartz, of ''Series/GilligansIsland'' and ''Series/TheBradyBunch'' fame, created it.
* TimeTravel
* TrappedInThePast, turning into GetBackToTheFuture when they fix their spacecraft.