The Old Farmer's Almanac is a beloved North American periodical published every September, offering weather forecasts, planting charts, astronomical data, recipes, and predictions on trends in fashion, food, and technology. Founded by Robert Bailey Thomas in 1792, it is the oldest continuously published periodical in North America and is often called a "gardener's bible." Its famous weather predictions rely on a secret forecasting formula, developed by Thomas and kept in a black tin box in Dublin, New Hampshire, which remains in use today. The almanac's history includes a notable anecdote where Abraham Lincoln may have used a copy in an 1858 murder trial to challenge eyewitness testimony about the moon's position, though the exact almanac used is disputed. Over time, it evolved from a farming-focused guide to a general-interest publication, featuring a trademarked "four seasons" cover design since 1855 and now published by Yankee Publishing Inc., which also issues a Canadian edition.