My husband (James) was recently named to our town's Tree Committee (yes, that's a thing). Our adult child told him that there was a Peanuts television special about Arbor Day that he would probably be interested in. He found a copy for purchase on DVD and we await its arrival. Meanwhile he also found a used copy of the book version for purchase and had it sent to our house. (I also discovered that our local public library has a copy on DVD; I always check the library before buying.)
This full-color comic features Sally being humiliated when asked in class to tell what Arbor Day is and responds that it's the "day that all the ships come sailing into the arbor". Assigned to write a report about Arbor Day she seeks Linus' help who suggests a trip to the library where he's sure there are "some books about Arbor Day". What follows are several pages of images of Sally and Linus doing research at the library, as well as some shots of Snoopy and Woodstock laughing at a book on dog obedience training, and playing with the photocopier, which gets them kicked out.
I look forward to celebrating Arbor Day is year on April 28. I guess that's what my elementary school was celebrating in the 70s when they used to give us saplings to take home and plant. Otherwise, I don't recall ever recognizing it.