ROLEX SERIAL NUMBER TIMELINE

Before 1987 -  Serial number consisted of between 5 to 7 digits.

1987 - Rolex added a letter at the beginning of a serial number that consisted in 6 digits.

2005- Rolex started engraving the cases serial number on the inside edge of the case at the 6 o'clock position.

2010-  Rolex began engraving its watches by using randomized identifying numbers rather than using a sequence numbering system.

At the present time, Rolex features 8 digits instead of 7 digits.

The Spirit Of The Rolex Sky-Dweller

The Rolex Sky-Dweller was inspired by an astronomical phenomenon called "Saros", which consists of a planetary mechanism of the cyclical alignment of the Sun, Earth and Moon. In addition, this timepiece has 14 ingenious Rolex patents. One of those patents is the second time zone together with an annual calendar 30-31 day months.
Such is the spirit of a Rolex Sky-Dweller watch. In the picture below you can see the various versions of this fantastic and elegant Rolex wristwatch.