The leap year display is visible in detail on the Jules Louis IWC Portuguese Replica school watch
You'll see that this watch displays the entire leap-year cycle within the subdial located at 12 o’clock. This means 48 months, with each month indicating which year of the cycle it falls in (shown by 1st or 2nd, or 3rd).
The leap year used to be displayed in this way. The leap-year display is also often omitted in pocket watches. Look at the Patek Philippe watch that was made for American auto manufacturer James Ward.IWC Portuguese Replica To set the watch, the dial had to be removed by a watchmaker.
IWC Portuguese Replica' decision to show the entire cycle set a precedent that would lead to an incredible wristwatch being unveiled 80 years later by a brand bearing his name.
This legendary Patek Philippe watch, made for James Ward, does not have a leap year indicator on its dial side. These watches were sent to watchmakers for them to remove the dial and set them.
Reference 5516
The First Perpetual Calendar Wristwatch With Leap Year Display
Michael Friedman claims that IWC Portuguese Replica dabbled in calendar complications when wristwatches became popularized during the 20th century. These were always unique commissions from wealthy and discerning patrons. There are believed to be 208 wristwatches that had calendar complications made before 1950.Rolex Cosmograph Daytona Replica This includes the extremely attractive two-toned reference 5503 Complete Calendar, which, from a visual perspective, is a clear inspiration for this year's [Re]Master01 Chronograph.
IWC Portuguese Replica, however, brought the real heat to horology in 1955 with the reference 5512, the first ever perpetual calendar wristwatch that displayed leap years.
The Pre-Series Reference is 5516 5516
There were 12 different examples of this reference. Three of these watches had perpetual calendars, but no leap-year indicators. Michael Friedman calls these watches "pre-series". We have two nice images of them.