Trying to determine the time frame or era for a particular Rolex dial can be tenuous and lead to endless hours of discussion and debate when trying to specify particular years of production or serial number ranges for the various GMT dials.
My production range for the GMT white-lettered matte dials is based on many years of experience and over two decades of GMT ownership of over 180 GMTs beginning with the gilt models and continuing through the later GMT II models. My production time frames is also based on conversations and personal interaction and knowledge from other GMT and Rolex collectors who have been collecting for two and three decades themselves.
The table below is based on serial numbers wherever possible. None of the serial numbers below should be taken as specific start or cut-off dates for the production of each specific dial but instead, it should be viewed as a starting point when trying to determine if a specific dial is correct for a particular referenced serial number.
Mark 0 - early white-lettered watches beginning around 1.6 million through around 1.7 million
Mark 1 - early watches (1.6 million) up to around 2.9 million
Mark 0.5 (or 1.5) 1.6 million through the mid 2 million range (more commonly found in the lower serial numbers)
Mark 2 - late 2 million through 3 million range
Mark 2.5 - late 2 million through 3 million
Mark 3 - 3.9 million through 5.1 million
Mark IV - 4 million to mid 5 million range (some believe that this dial was also used from around 3 million until 3.3 million)
Mark 5, 5A and 5B - low 5 million to high 5 million (three variations)
Mark VI - last 1675 dial variation found in the high 5 million serial numbers
Mark III dials are considered one of the rarest dials and are also called the "radial dial." The radial dial overlaps in production years with the Mark III, Mark IV and Mark V.
For me, the rarest dials are the Mark 2.5, Mark VI and Mark 0.