So Mrs. CW told me just now that it was "about time" for some more coffee, and I responded with "It's about time, it's about space, it's about two men in the strangest place!"
She looked at me quizzically, so I told her it was the ditty to a TV program I watched as a kid about two astronauts that went back in time to the dinosaur age. She had no memory of such a thing.
So, using the power of the internet, I looked it up. It was indeed a comedy show on CBS that lasted for one season in 1966/67. I was six years old, and apparently the opening line stuck in my juvenile brain, never to dislodge until this morning when my wife's random comment knocked it loose.
Does anyone else remember this show?