Saturday mornings growing up meant waking up far earlier than I would on a school day so I could enjoy a healthy dose of cartoons. I stuck mostly with ABC, as they showed the various incarnations of "The Superfriends." I'd switch to NBC for some "Spider-Man and his Amazing Friends," and in the early years, CBS was the place for watching classic Warner Bros. cartoons. Eventually ABC got that, too, but it wasn't the same.
The networks all had their own vaguely educational interstitial segments, and ABC won my allegiance here, too, if just for "Schoolhouse Rock." Coming in a strong second were the "Time for Timer" spots. I never saw the full-length cartoon from which they spun off, but I enjoyed watching the strange little blob and his obsession with nutrition.
Timer was voiced by Lennie Weinrib, who passed away recently. His voice acting rap sheet was quite long; if you watched Saturday morning TV any time in the 70s and early 80s, you heard him. You can learn more from his friend, the always-cool Mark Evanier.
Here for your amusement (until YouTube yanks them away), I've found the "Time for Timer" spots. Check them out while you can. I saved my favorite for the last one, of course.
You Are What You Eat
Sunshine on a Stick
The Only You You've Got
Eat Some Kind of Breakfast Every Day
I Hanker for a Hunk of Cheese