The Oyster Perpetual Datejust is the epitome of the classic watch, distinguished by its timeless style and exceptional elegance.
Rolex’s Datejust is the archetype of the classic watch thanks to functions and aesthetics that never go out of fashion. At its launch in 1945, it was the first self-winding waterproof chronometer wristwatch to display the date in a window at 3 o’clock on the dial – hence its name. It consolidated all the major innovations that the brand had contributed to the modern wristwatch until then – chronometric precision (first chronometer certificates granted to a Rolex wristwatch as of 1910), waterproofness (creation of the Oyster case in 1926) and self-winding (mechanism via Perpetual rotor patented in 1931). The Datejust has spanned eras while retaining the enduring aesthetic characteristics that make it so instantly recognizable.
INSTANTANEOUS DATE AND CYCLOPS LENS
The Datejust revolutionized wristwatch date display. Traditionally, the date was indicated by a hand pointing to markings around the edge of the dial. With the Datejust, Rolex introduced a calendar that displayed the date via a disc in a window at 3 o’clock. This would become the watchmaking standard. In 1953, the Cyclops lens was added to the crystal, magnifying the date for easy reading. In 1956, the date change became instantaneous. Rapid, secure setting of the date by turning the winding crown in either direction was introduced in 1977 on models of the Datejust equipped with a medium-sized or large calibre, then from 1983 on Datejust models fitted with a small movement.
THE DATEJUST, SUPERLATIVE CHRONOMETER CERTIFIED
Like all Rolex watches, the Datejust is covered by the Superlative Chronometer certification redefined by Rolex in 2015. This exclusive designation testifies that every watch leaving the brand’s workshops has successfully undergone a series of tests conducted by Rolex in its own laboratories and according to its own criteria. These certification tests apply to the fully assembled watch, after casing the movement, guaranteeing superlative performance on the wrist in terms of precision, power reserve, waterproofness and self-winding. The Superlative Chronometer status is symbolized by the green seal that comes with every Rolex watch and is coupled with an international five-year guarantee.
The precision of every movement – officially certified as a chronometer by the Swiss Official Chronometer Testing Institute (COSC) – is tested a second time by Rolex after being cased, to ensure that it meets criteria for precision that are far stricter than those of the official certification. The precision of a Rolex Superlative Chronometer is of the order of −2/+2 seconds per day – the rate deviation tolerated by the brand for a finished watch is significantly smaller than that accepted by COSC for official certification of the movement alone.
The Superlative Chronometer certification testing is carried out after casing using state-of-the-art equipment specially developed by Rolex and according to an exclusive methodology that simulates the conditions in which a watch is actually worn and more closely represents real-life experience. The entirely automated series of tests also checks the waterproofness, the self-winding capacity and the power reserve of 100 per cent of Rolex watches. These tests systematically complement the qualification testing during development and production, in order to ensure the watches’ reliability, robustness, and resistance to magnetic fields and shocks.
THE OYSTER CASE, SYMBOL OF WATERPROOFNESS AND ELEGANCE
The Datejust’s Oyster case, 31, 36 or 41 mm in diameter and guaranteed waterproof to a depth of 100 metres (330 feet), is a paragon of robustness and elegance. The middle case is crafted from a solid block of Oystersteel, a particularly corrosion-resistant alloy, or from 18 ct gold. The case back, edged with fine fluting, is hermetically screwed down with a special tool that grants only certified Rolex watchmakers access to the movement. The Twinlock winding crown, fitted with a double waterproofness system, screws down securely against the case. The bezel can be smooth, domed, fluted or set with diamonds. The crystal, with a Cyclops lens at 3 o’clock for easy reading of the date, is made of virtually scratchproof sapphire and benefits from an anti-reflective coating. The waterproof Oyster case provides optimum protection for the Datejust’s movement.
PERPETUAL CALIBRES 2236 AND 3235
Datejust models are equipped with calibre 2236 (Datejust 31) or calibre 3235 (Datejust 36 and Datejust 41), self-winding mechanical movements entirely developed and manufactured by Rolex. Consummate demonstrations of technology, these movements carry a number of patents. They offer outstanding performance in terms of precision, power reserve, resistance to shocks, convenience and reliability.
The oscillator of calibres 2236 and 3235 has a balance wheel with variable inertia regulated extremely precisely via gold Microstella nuts. It is held firmly in place by a height-adjustable traversing bridge enabling very stable positioning to increase shock resistance. The oscillator is also fitted on high-performance Paraflex shock absorbers, designed by Rolex and patented.
Calibre 2236 incorporates a Syloxi hairspring in silicon, which is manufactured by the brand and patented. Calibre 3235 features an optimized version of the blue Parachrom hairspring, manufactured by Rolex in a paramagnetic alloy. Both hairsprings are insensitive to magnetic fields, offer great stability in the face of temperature.
The geometry of the Syloxi hairspring found in calibre 2236 guarantees the regularity of the movement in any position; the blue Parachrom hairspring of calibre 3235 is fitted with a Rolex overcoil that offers the same level of performance.
Calibre 2236 features a paramagnetic nickel-phosphorus escape wheel. Calibre 3235 incorporates the patented Chronergy escapement, made of the same alloy, which combines high energy efficiency with great dependability and is also insensitive to magnetic fields.
Calibre 2236 and calibre 3235 are fitted with a self-winding module featuring a Perpetual rotor, which ensures continuous winding of the mainspring by harnessing the movements of the wrist to provide constant energy. Calibre 2236 offers a power reserve of approximately 55 hours, while the power reserve of calibre 3235 extends to approximately 70 hours thanks to its barrel architecture and the escapement’s superior efficiency.
The Datejust’s movements will be seen only by certified Rolex watchmakers, yet they are beautifully finished and decorated in keeping with the brand’s uncompromising quality standards.
OYSTER, JUBILEE AND PRESIDENT BRACELETS
Depending on the version, the Datejust 31 is available on a three-piece link Oyster bracelet with an Oysterclasp; on a five-piece link Jubilee bracelet – created in 1945 especially for the Datejust – with a Crownclasp; or on a three-piece link President bracelet with a Crownclasp. The Datejust 36 and the Datejust 41 are, depending on the version, available on a three-piece link Oyster bracelet or a five-piece link Jubilee bracelet fitted with an Oysterclasp. A concealed attachment system ensures seamless visual continuity between the bracelet and case.
Bracelets equipped with an Oysterclasp also feature the Easylink comfort extension link, developed by Rolex, which allows the wearer to easily increase the bracelet length by approximately 5 mm, for additional comfort in any circumstance.
The President bracelet, fitted on all of the 18 ct gold versions (Datejust 31), includes ceramic inserts inside the links to enhance its flexibility and longevity.