The Datejust is the watch that made a date window ordinary: in 1945 it was the first self-winding, waterproof, chronometer-certified wristwatch to show the date, and the Cyclops lens that magnifies it arrived to solve the reading problem the date itself created. At 31mm it is the mid-size case in the line. Calibre 2236 uses Rolex's silicon Syloxi hairspring. Water resistant to 100m. Configuration is where this reference lives: Oystersteel with white gold, Everose, and gem-set executions; Jubilee bracelet — designed for the Datejust in 1945 — or Oyster; and dials from bright black to mother-of-pearl. Those are choices about the individual watch, not different references. What matters on examination: bracelet stretch, which a Jubilee shows sooner than an Oyster because of its five-piece links; case and lug sharpness; that the dial, hands and date wheel are of one period; and on a gem-set execution, that the papers record the stone configuration and the setting is even. Confirmed through the desk. Maker: Rolex. Reference: 278274-0007. Available through ELITA's private desk — verification review, discreet handling and storage. Price on request.