The Rolex Datejust is the brand's most varied watch, and the reference number on its papers decodes most of that variety. On current six-digit references, the first digits tell you the size and generation, and the last digit tells you the metal. Learn to read those two parts and you can compare any two Datejusts in seconds, then choose size, bracelet and dial by eye.
Why the Datejust Matters
Rolex introduced the Datejust in 1945 as a self-winding, waterproof chronometer wristwatch with the date shown in a window on the dial. The magnifying Cyclops lens over the date followed in the 1950s. The basic formula has hardly changed since: an Oyster case, a date at three o'clock, and a choice of bezels, dials and bracelets that lets the same watch read sporty, classic or dressy. That range is exactly why buying one takes a little homework.
How to Read a Datejust Reference Number
Take a reference like 126331. On the current generation:
- The opening digits give the family, size and generation. References beginning 1263 are the Datejust 41. References beginning 1262 are the current Datejust 36. References beginning 1162 are the previous-generation Datejust 36. References beginning 2782 are the Datejust 31.
- The last digit gives the metal. A 1 means Everose Rolesor, Oystersteel with 18K Everose gold. A 3 means yellow Rolesor, Oystersteel with 18K yellow gold. A 4 means white Rolesor, Oystersteel with an 18K white gold bezel. A 0 means all Oystersteel.
So 126331 is a Datejust 41 in Everose Rolesor, 126333 is the same watch in yellow Rolesor, and 126334 is the steel version with a white gold fluted bezel. A 278271 is a Datejust 31 in Everose Rolesor. The full reference also carries a dial and bracelet code after a dash on the papers, which pins down the exact configuration.
Choosing a Size: 31, 36 or 41 mm
Size is the first decision, and the most personal one.
- Datejust 31: a classic size on a smaller wrist, and the Datejust most often chosen as a dress watch or a first fine watch. See this unworn Datejust 31, reference 278271.
- Datejust 36: the original size, and the most versatile. It sits comfortably on almost any wrist and reads as a classic rather than a statement. See the Datejust 36, reference 126231, or the previous-generation Datejust 36, reference 116234.
- Datejust 41: introduced in 2016, and the choice for a larger wrist or a more modern presence. See the Datejust 41, reference 126331, or the steel and white gold 126334.
If you are between sizes, the bezel matters: a polished fluted bezel catches light and makes a watch look larger, while a smooth bezel reads smaller and quieter.
Choosing a Metal
All-steel and white Rolesor watches are the most discreet; from a distance, the white gold bezel of a white Rolesor reads as bright steel. Yellow Rolesor is the classic two-tone look, with gold on the bezel, crown and center bracelet links. Everose Rolesor does the same with Rolex's rose gold alloy, for a warmer, softer contrast. None is objectively better. Choose the metal that matches the jewelry you already wear most.
Oyster or Jubilee Bracelet
The Oyster bracelet has three broad, flat links and a sportier, more solid feel. The Jubilee has five smaller links and drapes more like jewelry, with more flex on the wrist. On a two-tone watch, the Jubilee shows more gold. The bracelet is part of the full reference on the papers, so a listing should say which one the watch wears.
Movements and Generations
Current Datejust 36 and 41 references use calibre 3235, with about 70 hours of power reserve, meaning the watch keeps running for nearly three days off the wrist. The previous-generation Datejust 36 references use calibre 3135, with about 48 hours. Both are robust, serviceable movements; the newer one simply runs longer between wears. The month and year in our listing titles, such as January 2018 or February 2025, is the date on record for that watch, and the reference tells you which movement it has.
What to Check on a Pre-Owned Datejust
- The reference and serial match the papers. If the watch has box and papers, the reference and serial on the card should match the watch. Our guide to Rolex box and papers explains what the paperwork does and does not prove.
- The bezel. Fluted gold bezels show dings and wear on the edges of the flutes. A sharp, even fluting is a good sign.
- The bracelet stretch. Hold the watch case and let the bracelet hang. Visible sag between links means wear in the pins, especially on older Jubilee bracelets.
- The date change. The date should snap over cleanly around midnight.
- Service history. Ask when the watch was last serviced. A recent service is a plus, not a requirement, on a modern movement.
Shop the Rolex Datejust
Every watch in our Rolex collection is examined before listing, and each listing states its reference, case size, dial, bracelet, whether it is unworn or pre-owned, and whether it comes with box and papers. You can also browse every brand in our timepieces collection. Watches ship free and insured, and may be exchanged within 7 days.
Frequently asked
What does the last digit of a Rolex Datejust reference mean?
On current Datejust references, the last digit indicates the metal: 0 for Oystersteel, 1 for Everose Rolesor, 3 for yellow Rolesor, and 4 for white Rolesor, which is steel with an 18K white gold bezel.
Which Datejust size should I choose?
The 36 mm is the original and most versatile size. The 41 mm suits a larger wrist or a more modern look, and the 31 mm suits a smaller wrist or a dress watch. A fluted bezel makes any size look slightly larger.
What is the difference between Rolex calibre 3235 and 3135?
Calibre 3235 is the newer movement in current Datejust 36 and 41 references, with about 70 hours of power reserve. Calibre 3135 powered the previous generation, with about 48 hours.