 It also featured the company's waterproof Oyster case (first introduced in 1926), a fluted bezel, and the new Jubilee bracelet (so named for the occasion).Over the years, the Datejust saw an expansion of its design options as well as improvements to its movement, from a gradual date change shortly before midnight in the earliest versions to an instantaneous change beginning in 1955.Also in 1955, two years after its debut, Rolex added the now famous Cyclops lens as a major update.