I wish I knew exactly when this was airing. we didn't get a Gamera week when I was growing up. It had to be in the 80s, since Gamera: Super Monster (1980) wasn't released in this country til 2 or 3 years after it's Japanese theatrical run. it was at least '84 when it aired in Colorado.
I find it interesting that they saved the best Gamera movies for last- Guiron and Jiger. I would have watched all five movies, especially the second one, as that never aired in my area at all, so I would have loved seeing that.
the other interesting thing is that every one of the ads used Barugon and Gamera, as you can see here. not one of the other enemy monsters was used. I wonder what the thinking behind that was, it's not like Barugon was any less outlandish than Gyaos, Jiger or Guiron. I'm sure the reason is lost in time by now.