At 31 mm, the Datejust 31 wears the classic Oyster architecture: a monobloc middle case, screw-down case back, and screw-down Twinlock winding crown delivering waterproofness to 100 metres / 330 feet. The case and Jubilee bracelet are both crafted in Yellow Rolesor, Rolex's combination of Oystersteel and yellow gold, with the bracelet fastening via a concealed folding Crownclasp. A scratch-resistant sapphire crystal with a Cyclops lens over the date sits above the dial.
The olive green dial features a floral motif set with 24 diamonds in 18 kt gold settings, while the domed bezel is itself set with diamonds, lending the piece a consistently jewelled character. Roman numerals appear on the dial alongside centre hour, minute, and seconds hands, with an instantaneous date display and stop-seconds function for precise setting.
Inside runs the Calibre 2236, a perpetual mechanical self-winding movement produced by Rolex, certified as a Superlative Chronometer to a precision of -2/+2 seconds per day after casing. The oscillator incorporates a Syloxi silicon hairspring with patented geometry and Paraflex shock absorbers, while bidirectional winding via the Perpetual rotor provides a power reserve of approximately 55 hours.
