I read this short story in the 70's I think. It was about time travel tourists that would go back in time to the best event of that season. I recall Charlemagne's crowning as Holy Roman Emperor at Xmas being the Winter event. Can't recall anything else about the story...
Possibly Vintage Season by Henry Kuttner and C.L. Moore.
Oliver Wilson is renting an old mansion to three vacationers for the month of May. He wants to get rid of them so he can sell the house to someone who has offered him three times its value, provided the buyer can move in during May. His fiancée, Sue, insists that he arrange for them to leave so that he can sell the house, giving them enough money for their impending marriage.
The tenants are a man, Omerie Sancisco, and two women, Klia and Kleph Sancisco. They fascinate Oliver with the perfection of their appearance and manners, their strange connoisseur's attitude to everything, and their secretiveness about their origin and about their insistence on that house at that time. Oliver's half-hearted attempts to evict them flounder when he becomes attracted to Kleph. The mystery deepens with remarks she lets slip, with the unspectacular but advanced technology of things she has in her room—including a recorded "symphonia" that engages all the senses with imagery of historical disasters—and with the appearance of the would-be buyers, a couple from the same country, who plant a "subsonic" in the house intended to drive the residents out.
Hearing Kleph sing "Come hider, love, to me" from the Prologue to Chaucer's Canterbury Tales, Oliver realizes that she and her friends are time travelers from the future. He traps Kleph into admitting they are visiting the most perfect seasons in history, such as a fall in the late 14th century in Canterbury.
One of the times the travellers visit is indeed Charlemagne's coronation.