The Patek Philippe Annual Calendar is a celebrated Swiss luxury watch that introduced a groundbreaking complication when it debuted in 1996. Designed to automatically adjust for months with 30 and 31 days, the annual calendar requires correction only once a year at the end of February. Known for its elegant dials displaying the day, date, and month, the collection combines practical innovation with Patek Philippe’s timeless design. Available in stainless steel and precious metals, with options including moon phase and chronograph features, these watches are powered by sophisticated automatic movements. Collectors value the Annual Calendar for its blend of technical mastery and everyday usability, making it one of Patek Philippe’s most admired modern complications.