The Philippe Patek company has been making fine watches since 1839 and continues to be market leaders in the field of luxury, finest-quality watches. Older Philippe Patek watches are collectors' items, and the condition and age of your watch will tell a lot about the history and value of the timepiece you have. With luck, you may find your piece to be worth tens of thousands of dollars.
Open up the watch.The approach required to open the watch will depend on the design of the watch. Look for hinges or pry points and open with a small screwdriver. If the watch lacks either and has only a seam, try opening the watch by unscrewing it.
Locate the serial number, which will be engraved into the movement -- the moving parts of the watch -- or the back of the case. If you find numbers on both, cross-reference the two. If they differ, then the movement or case may have been replaced and they were manufactured at different times.
Compare the serial number against a catalog that cross-references serial numbers with the production date. This will give you a five year span within which your watch was produced. These dates are only approximate, and serial numbers at the beginning and end of the ranges may have been produced at the end of the previous five year span or the beginning of the following one.
Contact a specialist dealer or appraiser for a precise dating of the piece beyond the determination of year by serial number.