Rolex · Day-Date 36

Strap for Day-Date 36 Yellow Gold Fluted / Oyster / Bull's Eye

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
Reference118238-0420
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 118238-0420

Selected for the 20 mm lug width · workshop selection

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The Day-Date 36 118238-0420, seen from the bench

The Rolex Day-Date 36 in yellow gold (ref. 118238-0420) combines classic proportions established in 1956 with modern construction. The 36mm case houses the Rolex 3155 caliber with Chronometer certification, Chronergy escapement, and blue Parachrom balance wheel. The champagne dial displays date and day of week simultaneously in windows. Water resistance reaches 100 meters. The integrated Oyster bracelet features full gold links with a 20mm lug width, designed to balance the case diameter for optimal visual proportion.

Frequently asked questions

What is the lug width of the Rolex Day-Date 36 reference 118238-0420?

The Day-Date 36 reference 118238-0420 features a lug width of precisely 20 millimetres, measured from the inner edges of the spring bar attachment points. This dimension is model-specific and ensures compatibility with aftermarket straps specifically engineered for 20mm lugs.

Which strap material is ideal for the Day-Date 36 in yellow gold?

Black or brown alligator provides refined contrast and formal aesthetics. Vegetable-tanned calf develops a patina that ages in parallel with the gold. Shell cordovan in cognac or burgundy tones introduces natural luminosity. For summer wear, khaki canvas NATO or vulcanised rubber guarantee practicality without aesthetic compromise.

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

Obtain a spring bar removal tool in satin steel. Position the watch with the strap facing downward, insert the pointed tip beneath the metal pin attachment, apply gentle downward pressure until the internal spring releases, and remove the pin. Repeat on the opposite lug. Insert the new pins through the strap and into the case holes, pushing until you feel the spring mechanism reset.

Is an aftermarket 20mm strap truly compatible with the Day-Date 36 118238-0420?

Yes, completely. Any strap with a 20-millimetre lug width, manufactured to correct constructional standards, will fit with millimetre-level tolerances. Always verify the strap is explicitly labelled for 20mm lugs and that the supplier—such as Casati Milano—guarantees certified manufacturing quality.

How long does a natural leather strap last on a Day-Date 36 worn daily?

A quality alligator strap, worn daily under normal conditions, lasts typically 3–5 years. Vegetable-tanned calf, less resistant to moisture, has a lifespan of 2–4 years. Shell cordovan can last 4–6 years due to its density. Duration depends on perspiration, humidity, frequency of wear and preventative care. Casati Milano offers an 18-month guarantee against manufacturing defects.

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