Cal. 3255 is the current day-date movement from Rolex. Part of the updated Chronergy family, it features 3-day power reserve and many new components. Cal. 3255 first appeared in 2015 in the Day-Date 40 and has since been released in the Day-Date 36 as well. It replaced the Cal. 3155 and Cal. 3156.
- Rolex Day-Date 40 (2015-present), Ref. 228200, 228300
- Rolex Day-Date 36 (2019-present), Ref. 128200, 128300
Although widely reported to be 28.50 mm in diameter like the other Chronergy movements, Cal. 3255 has a visibly-larger main plate like Cal. 3156 and the other oversized movements in the Cal. 3100 family. This accommodates larger day and date wheels for the 40 mm Day-Date 40. Since the 36 mm Day-Date 36 uses the same movement, it is likely that this movement uses a smaller main plate for its smaller day and date wheels.
This movement is described by Rolex as a “Superlative Chronometer.” The company uses this term to indicate their most accurate modern movements. They claim that these are twice as accurate as any official chronometer certification, to -2/+2 seconds per day “after casing.” The Superlative Chronometer test is performed in-house and goes beyond COSC procedures.
Rolex introduced the Chronergy family in 2015 with Cal. 3255, an updated movement for the famous Day-Date (President) model. It is a major redesign, with Rolex claiming that over 90% of the components are redesigned or all-new. The marquee feature for consumers is the “3-day” (70 hour) power reserve, which is made possible by the “Chronergy escapement” with optimized gears and lubricants as well as a longer mainspring inside a thinner barrel. Other notable features include more efficient automatic winding, unrestricted calendar correction, and “backward” (counter-clockwise) time setting.
The movement can be manually wound with the crown in position 1. Rotate the crown clockwise to wind the mainspring.
The day and date wheels are advanced with the crown in second position (one notch out). Turn the crown clockwise to advance the date wheel by one day. Turn the crown counter-clockwise to advance the day wheel.
The time is set with the crown in third position (pulled all the way out). Rotate the crown counter-clockwise to advance the minute and hour hands and clockwise to turn them backward.