Rolex · Day-Date 36

Strap for Day-Date 36 Yellow Gold Diamonds / President / Paved Roman

Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width20 mm
Case diameter36 mm
Reference118388-0043
FamilyDay-Date 36
MovementRolex caliber 3155 hours, minutes, seconds | date, day | chronometer
CaseYellow Gold

Recommended spring bar

Spring bars Rolex Daytona 116520 — 20mm steel

Technical match for lug width and diameter · lug 20 mm · Ø 1.5 mm · closed lugs

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Straps for the Day-Date 36 118388-0043

Selected for the 20 mm lug width · workshop selection

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The Day-Date 36 118388-0043, seen from the bench

The Rolex Day-Date 36 Yellow Gold Diamonds ref. 118388-0043 features an 18-karat yellow gold Oyster case with baguette-set bezel and a 36 mm diameter. Introduced in 1956, it was the first automatic wristwatch to display both day and date simultaneously. The Rolex caliber 3155 is a fully integrated automatic movement with variable-inertia balance wheel and Chronergy escapement, providing 48 hours of power reserve and COSC-certified precision. Water-resistant to 100 meters with a closed caseback, it requires a 20 mm lug width strap for compatibility.

Frequently asked questions

What is the lug width of the Rolex Day-Date 36 118388-0043?

The lug width of the Rolex Day-Date 36 reference 118388-0043 is 20 mm. This measurement is taken using a digital calliper positioned inside the lugs, parallel to the case edge. Any aftermarket strap of 20 mm with curved ends will be compatible with this reference.

What is the best strap for the Rolex Day-Date 36 118388-0043?

For the 18-carat yellow gold case of the Day-Date 36, the most suitable materials are polished alligator leather in bordeaux or dark tobacco, natural shell cordovan, and vegetable-tanned calf leather in cognac or honey tones. A yellow gold deployant clasp maintains the metallic coherence of the dial and protects the leather from daily wear.

How do I change the strap on a Rolex Day-Date 36?

The strap on the Rolex Day-Date 36 is secured via 20 mm spring bars fitted into the Oyster case lugs. A fine-tipped spring bar tool is sufficient to compress the bars and release the strap. Care should be taken to avoid scratching the gold case. If in doubt, it is advisable to entrust the operation to a watchmaker or to the Casati Milano atelier.

Are there aftermarket straps compatible with the Rolex Day-Date 36 118388-0043?

Yes. The quality aftermarket offers 20 mm straps with curved ends specifically designed for the lug geometry of the Day-Date 36. Milanostraps.it provides a selection of handcrafted straps in alligator, shell cordovan, calf leather and rubber, available bespoke or ready to ship, all compatible with this reference.

How long does a leather strap last on a Rolex Day-Date 36?

The lifespan of a leather strap depends on leather quality, frequency of use and exposure to perspiration and environmental factors. A high-quality alligator or shell cordovan strap, worn regularly but not daily, retains structural and aesthetic integrity for 3 to 5 years. Vegetable-tanned leather develops its own patina over time, increasing perceived value. Casati Milano's guarantee covers manufacturing defects for 18 months.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

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Casati Milano · Via XX Settembre 15, Milan · by appointment only