''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.
* AnimatedCreditsOpening: Revamped with its plot points reversed after the {{Retool}}.
* ComicBookAdaptation: One issue long.
* ContemporaryCaveman
* 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
* 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.