Rolex Clasp Codes

For a long time nobody knew what the letters on the clasps meant, because Rolex doesn't release any official information on them. Matthias from the R-L-X forum came up with a theory, and a lively discussion largely confirmed it. According to it, the letter or letter combination is the year the clasp was made, and the number is the month ("1" for January up to "12" for December). An added "S" marks a replacement clasp, similar to replaced sapphire crystals.

This is how the theory describes the markings, based on what we know so far. The table rests on a broad base of data from members of the R-L-X forum, but it's still an educated guess, so there's no guarantee it's right. Keep in mind that the dates refer to when the clasp was made. The watch could have been sold quite a bit later.

* These letters were filled in to complete the sequence and haven't been confirmed.

Since 2011 Rolex has assigned the codes at random: three characters, letters and numbers. You can't tell the year of production from them anymore.