Given that one of the major themes in Dandelion Wine is happiness, and that almost every chapter is a short story with its own happy ending, it would be a real rip-off if the book didn't end happily. Thankfully, Bradbury doesn't disappoint. Phew.
When Doug asks Tom about happy endings, Tom tells him that going to bed every night means that every day ends happily. And sure enough, Dandelion Wine ends with Doug going to bed in the same room in which he awakens at the beginning, performing the same ritual: He pretends to turn off the lights in the houses just as he pretends to turn them on in the morning, bestowing a happy ending upon Green Town before settling down for his own.
Dandelion Wine begins at the beginning of summer 1928 and ends at the end, as Doug is preparing to go back to school… and already fantasizing about summer 1929. Sweet dreams, Doug.