Introduced in 1977, Cal. 3055 increased the beat rate to the modern 28,800 A/h in the famous Rolex Day-Date range. This replaced the Cal. 1056, which had been used since 1965. It was replaced in 1988 with the 31-jewel Cal. 3155.
Used in the model Rolex Oyster Perpetual Day-Date.
Although the date is quickset in crown position 2, the day function is not quickset.