Patek Philippe Annual Calendar 5035J-020 2001 [Preowned]Overview The Patek Philippe Annual Calendar reference 5035J 020 holds a special place in modern watchmaking historynot merely as a beautiful timepiece, but as a technical milestone. Introduced in 1996, the 5035 was the worlds first wristwatch to feature an annual calendar complication, a concept pioneered and patented by Patek Philippe. This innovation brilliantly bridges the gap between traditional calendars and more complex perpetual calendars,