An ombre dial is darkest at its outer edge, which on this reference is exactly where the diamonds are. Reference 128399TBR is the 36mm Day-Date in white gold with the bezel set and the setting carried down onto the lugs, and this configuration puts a blue gradient dial inside that frame, with round diamonds in white gold settings at most hours and baguette-cut stones at six and nine. The stones sit at their brightest against the deepest part of the dial, and the gradient runs pale at the center where there is nothing to compete with it. The arrangement is not accidental. It is the reason the dial holds together instead of reading as two unrelated ideas.
A gradient dial is a single color applied so that its density increases from the center outward, sprayed rather than printed, and the difficulty is in the transition rather than in either end of it. Done badly it bands. Done properly there is no point at which the eye can say the change began. Blue is the color Rolex has committed to most heavily for this treatment, and on a white gold case it stays cool throughout, moving from a pale, almost silvered center to something close to navy at the rim. Around that perimeter, the round diamonds sit in white gold settings, each one raised slightly off the surface, and the baguettes at six and nine cut across the darkest band as horizontal bars. The case is 36mm in white gold with the bezel and lugs set with diamonds, so the outer edge of the watch is bright, the outer edge of the dial is dark, and the two meet at the ring where the markers sit. The bracelet is the President, semi-circular three-piece links in matching white gold with a concealed clasp. The day aperture sits at twelve, the date at three under the Cyclops lens. There is a practical consequence to the arrangement as well, which is that the hands stay legible across their entire sweep. A pale center means the tips of the hands are always crossing a light field near the middle of the dial and a dark one out at the edges, so neither end of a hand ever disappears into the background.
The day of the week is spelled out in full at twelve and the date sits at three, and both discs change instantaneously at midnight rather than sliding across the surrounding hour. The movement is self-winding with a power reserve of approximately 70 hours, which covers a weekend off the wrist with room to spare. Both calendar displays are corrected through the winding crown rather than by running the hands forward. The day disc is available in a long list of languages, specified at the time of order, and it is one of the few points at which a buyer can make a production Rolex specific to them. The Cyclops lens magnifies the date. On a gradient dial the two apertures are worth a second look, because the day window at twelve sits in the palest part of the dial and the date at three sits partway into the transition, so the printing on the discs has to be legible against two different backgrounds. The crown screws down against the case and the President clasp folds away entirely inside the links. Rolex prints both discs in a single color on this configuration rather than splitting them, which is the simpler solution and the one that holds up better against a dial changing tone underneath them.
The Day-Date arrived in 1956, was the first wristwatch to write the day of the week out rather than abbreviate it, and has never been made in steel. Gold and platinum only, which is the constraint that has shaped everything else about the model. Gradient dials are a comparatively recent addition and they have been among the more successful ones, because they give a solid-color dial a reason to change as the wrist moves without introducing a stone or a texture. The 128000 generation replaced the 118000 series in 2019 with a revised case, a cleaner bracelet taper and a longer running time. Within the generation, 128399TBR is a white gold reference where the diamond setting extends beyond the bezel and onto the lugs. Rolex builds the blue gradient twice on this reference, once with diamond markers and once with plain Roman numerals, and this is the set version. The difference between them is larger than a marker choice usually is, because the stones anchor the dark rim and the numerals do not. The gradient has aged well as a catalogue decision too. Where several of the brighter dial experiments of the past decade now read as period pieces, the blue gradient has stayed in production and spread across models rather than narrowing.
The buyer for this configuration is someone who wants a set dial without a stone dial. The gradient supplies depth and movement on its own, so the diamonds are marking hours rather than carrying the design, and that keeps the watch a step back from full jewelry territory while still being unmistakably set. It also photographs and wears differently from every other dial in the reference. Nacre shifts color, paving stays uniformly bright, and a gradient does neither, changing instead with the angle of the light across the whole surface at once. Collectors who arrive at the blue gradient usually looked at the paved dial first and decided against it, which makes this a considered choice rather than a default. At 36mm on the President bracelet it stays a dress watch, and the blue is deep enough at the edge to work with formal dress without looking like a novelty. It is also one of the few dials in the reference that photographs far worse than it wears, which is worth knowing before judging an example from images alone.
