Winnie the Pooh Discovers the Seasons (1981)

Storyline
Christopher Robin presents Pooh with an interesting new gift—a calendar. Pooh has never seen one before, and Christopher Robin explains that it's a way of keeping track of the days, weeks, months and seasons. The calendar stops at each season, as we watch Pooh, Piglet, Eeyore, Rabbit and Owl in the Hundred Acre Wood exploring the world around them and noticing the changes. Among them: the water in the pond becomes hard and slick when it gets cold.