At 31 mm, the Datejust 31 offers a refined scale that wears with quiet presence. The round case is crafted in Everose Rolesor — Rolex's combination of Oystersteel and Everose gold — and follows the Oyster architecture: a monobloc middle case, solid screw-down case back, and screw-down Twinlock winding crown for waterproofness to 100 metres / 330 feet. A scratch-resistant sapphire crystal with a Cyclops lens over the date window sits above the chocolate dial, which is set with diamonds in 18 kt gold settings, while the bezel is itself set with diamonds.
The Oyster bracelet, constructed from three-piece solid links in Everose Rolesor, closes with a folding Oysterclasp featuring an Easylink 5 mm comfort extension link. Inside, Caliber 2236 — a perpetual, mechanical, self-winding movement from Manufacture Rolex — delivers bidirectional winding via a Perpetual rotor and a power reserve of approximately 55 hours. The oscillator uses a Syloxi silicon hairspring with patented geometry and high-performance Paraflex shock absorbers, achieving a precision of -2/+2 seconds per day after casing. The movement is COSC certified.
Functions include centre hour, minute, and seconds hands, instantaneous date with rapid setting, and stop-seconds for precise time setting. Reference 278381RBR-0027 represents the Datejust 31 in one of its most distinctive dial and bezel configurations.
