It might seem almost quaint in the modern age, but the release of the Datejust in 1945 marked a massive innovation in watchmaking. As part of Rolex’s Oyster Perpetual family, it was both waterproof and self-winding. On top of that, it also displayed the date—the first watch in the world to nail all three.
That functionality, modest though it might seem now, is all present and correct inside the Date too.
Behind it all, obviously, is the caliber and both watches have worked their way through several during their respective durations.
For the 34mm Date, it started with the Cal. 1030. A legendary movement which debuted in 1950, it formed the base model of Rolex’s 1000 series, the brand’s first manufacture bi-directional winding mechanism. The 18,000vph chronometer certified caliber saw great service throughout the range during Rolex’s first true golden age, finding homes inside that era’s Submariner and Explorer series among others. Variations with additional complications built-in were fitted to the GMT-Master range, as well as both the Date and Datejust. As a smaller, more streamlined movement than the Aegler calibers powering the first of the Datejusts from the 40s, it meant the Date models were spared the domed case backs of the original Bubbleback watches.
In the following decade, the Date received an overhaul and an all-new mechanism, this time from the 1500 series that made its debut in 1957. Regarded by some purists as the finest range of movements Rolex has ever made, they became a mainstay of the company and were still in use inside some watches until the late 80s.
The Rolex Date had two different 1500 series calibers, the Cal. 1565 and Cal. 1575; both COSC-rated movements and very similar in functionality. The main differences between the pair were in frequency speed (18,000vph for the 1565, 19,800vph for the 1575) and the fact the latter model eventually gained a hacking function around 1972, allowing greater accuracy when setting the time by stopping the seconds hand when the crown was pulled out.
Like its predecessor, the 1500 calibers powered some of the biggest names in the brand’s lineup, and the engines that drove the Date also ran models such as the Explorer II, GMT-Master, the Submariner (which got its own date function in 1969) as well as the Sub’s big brother unveiled two years before, the iconic ref. 1665 Double Red Sea-Dweller.
Interestingly, if you were to open up the back of many of these 1565 or 1575-run machines, you would most likely see the winding bridge stamped with 1560 or 1570, the respective time-only base movements. It is the second 5 in the caliber’s reference number that designates them as date models, but as the winding bridges were interchangeable, many were used by Rolex in watches with the additional complication for convenience.
It wasn’t actually until the next upgrade that either the Date or the Datejust received their first calibers with a Quickset function. The previous series of movements had pioneered the cam and jewel system that produced an instantaneous date change at the stroke of midnight (‘just in time’—‘Datejust’) but the wearer still had to wind the hour hand through a complete 24-hour cycle to advance the date.
When the Cal. 3035 started work in 1977, it brought with it the ability to change the date independently via the crown in the second position. It was also the movement that ushered in the high beat 28,800vph frequency that produces Rolex’s famously sweeping seconds hand, and gives their watches even greater levels of accuracy and resilience.
Today, the full size Rolex Date is run by the Cal. 3135, arguably the Swiss giant’s most successful and widely-used movement, introduced in 1988. Along with the Quickset feature and hacking function, it is also at the leading edge of caliber technology, with its Glucydur balance wheel, an alloy of beryllium and copper, and the brand’s patented Parachrom bleu hairspring, said to be completely antimagnetic and 10 times more resistant to shocks.
The Date is certainly not the most complicated model you can buy, in terms of functionality. What it is though, is the end result of more than 60 years of constant efforts to make it the best at what it does, and you will rarely find another watch that can compete with it for sheer effortless timekeeping.