Rolex · Day-Date 36

Strap for Day-Date 36 White Gold / Fluted / Opal-Diamond / President-Diamond

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
Reference128239-0030
FamilyDay-Date 36
MovementRolex caliber 3255 hours, minutes, seconds | date, day | chronometer
Year2019
CaseWhite 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 128239-0030

Selected for the 20 mm lug width · workshop selection

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The Day-Date 36 128239-0030, seen from the bench

The Day-Date was introduced in 1955 as the first wristwatch to display the day and date in full. It features the automatic Caliber 3255 with hour, minute, second, date, and weekday functions, certified as a chronometer. 36mm case size with 20mm lug width.

Frequently asked questions

What is the lug width of the Rolex Day-Date 36 128239-0030?

The Rolex Day-Date 36 128239-0030 features a lug width of 20mm, measured from the interior of one attachment point to the other (internal lug width). This dimension is specific to this model and is not compatible with 22mm straps. To verify compatibility, measure the lug attachment points of your watch with a digital calliper.

What is the best material for a Day-Date 36 strap?

Alligator is the formal choice of excellence for the Day-Date 36 in white gold, thanks to its natural scute texture and the patina that develops over time. Alternatively, vegetable-tanned calf leather offers fine grain and natural ageing, whilst shell cordovan guarantees inherent lustre and notable resistance to wear. For more casual use, textile NATO or FKM rubber provides superior durability.

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

To change the strap, you must first remove the deployante (the folding clasp). Using a spring bar tool, gently press the lateral pin inward whilst extracting the lug attachment, performing the operation with deliberate movements. The same lugs are then inserted into the new strap, ensuring there is no play and that the clasp engages securely.

Is an aftermarket 20mm strap compatible with the Rolex Day-Date 36 128239-0030?

Yes, any 20mm strap constructed to artisanal standards is compatible, provided the lug attachments are correctly seated in the case lugs. It is essential that the strap is manufactured with precision: the internal diameter of the attachments must correspond to the original Rolex spring bar pins, without play or friction. MilanoStraps straps are built according to these tolerances.

What is the lifespan of a leather strap for a daily-wear watch?

A vegetable-tanned alligator strap, well maintained, lasts 4–6 years with daily wear. Calf leather has a slightly shorter lifespan (3–5 years) due to finer grain structure. Shell cordovan, owing to its structural density, reaches 6–8 years. Textile NATO resists beyond 10 years. FKM rubber lasts 5–7 years. These intervals vary based on humidity, sun exposure and frequency of wear. Regular maintenance (cleaning with a damp cloth, annual conditioning) significantly extends strap life.

The next step

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