Released in the year 1945, to mark the 40-year anniversary of the inception of Rolex, the Datejust is the best selling watch of Rolex. Intially, in honor of the Allied victory in WWII, Wilsdorf thought of naming it “The Victory", however it was changed to the “Jubilee" and Datejust , shortly thereafter. At first many thought that the Datejust was just a variation to the Bubbleback, which was released in the 1940's, and both were known as the Ovettone for its domed back.

A new fluted bezel with a larger crown replaced the coin edge bezel which was first introduced with the Datejust models. In the 1950's, Model 6605 of the Datejust was released. In this model, over the date on the watch's crystal, lies a cyclops or magnifying bubble. A Datejust model watch featuring a Turn-O-Graph gold Bezel, was released in 1956 by Rolex. This model was called the “Thunderbird", model 1625.

After much success, the Datejust which was only offered in 18kt yellow gold, now also offered in platinum or white gold, and stainless steel. The two-tone Datejust models were available in 1962. Also, the Datejusts offered a variety of options for the watch-straps. These included a leather watch-strap, an Oyster bracelet, or a Jubliee bracelet melrosejewelers.com.

A number of improvements led to a change in the original shape of the Datejust model during the 1970's. A person wearing a Datejust model could easily adjust the date function without having to turn the crown over and over again – this was an impressive feature called the “Quick-set". This feature was responsible in solving one of Rolex's major problems and by the year 1983, all Rolex models had this feature. In addition, Rolex eliminated the old domed plastic crystal and the new Datejust had sapphire crystal. This new feature drastically improved the aesthetics and longevity of the watch as it provided improved waterproof security and was scratch resistant as well. Furthermore, Rolex eliminated the old pie-pan dial and changed the dial and case to the sapphire crystal that had a smaller and slimmer profile.

Rolex also modified the earlier four-digit case reference number to a five digit number. Also during this time, the Oyster date, which was similar to the Datejust, was introduced. The only distinguishing feature was that it was 2mm smaller. The “midsize" version of the Datejust was available and was approximately 80% of the original size.