Cal. 3155 is an automatic movement with day and date used in the famous Rolex “President” Day-Date watch from 1988 through 2019. It was launched in 1988 in Ref. 118000, replacing Cal. 3055 in the Day-Date. The Day-Date was updated in 2000 but continued to use this movement, even as the Day-Date II launched with the larger Cal. 3156. Cal. 3155 continued in use in the 36 mm Day-Date until 2019 when the new Day-Date 36 with Cal. 3255 was introduced.
- 1988-2019 Rolex Day-Date, Ref. 118000, 118205, 118206, 118208, 118235, 118238, 118239
Note that many sources list the height of Cal. 3155 as being 6.00 mm (the same as the base Cal. 3135), the official Rolex parts document shows it as 6.45 mm.
Parachrom Update
Cal. 3155 was updated with the Parachrom hairspring between 2008 and 2010 but continued to use the Kif Elastor anti-shock device, unlike other Parachrom movements.