Rolex · Day-Date 36

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

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
Reference128239-0023
FamilyDay-Date 36
MovementRolex caliber 3255 hours, minutes, seconds | date, day | chronometer
Year2019
CaseWhite Gold

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Straps for the Day-Date 36 128239-0023

Selected for the 20 mm lug width · workshop selection

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The Day-Date 36 128239-0023, seen from the bench

The Day-Date was introduced in 1956 as the first wristwatch to display the day and date in full. It features the self-winding caliber 3255, certified chronometer, with functions of hours, minutes, seconds, date and weekday. 36mm case with 20mm lugs.

Frequently asked questions

What is the lug width of the Rolex Day-Date 36 128239-0023?

The lug width of the Rolex Day-Date 36 128239-0023 is 20 millimetres. This is the distance between the spring bars that attach the strap to the case. You can verify this by measuring directly between the two metal elements protruding from the case lugs. For a quality aftermarket strap, this dimension must be respected with absolute precision.

What is the best strap material for the Day-Date 36 128239-0023 in white gold?

Alligator remains the classical choice for the Day-Date 36 in white gold. Its natural texture in a grid pattern complements the brushed and polished tone of white gold while maintaining a discrete and formal aesthetic. Alternatively, calf leather with vegetable tanning offers a patina that evolves over time, acquiring depth and character. The choice depends on primary use: formal and urban wear suggests alligator, everyday professional use permits calf or rubber.

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

Changing the strap requires a specific tool called a spring bar tool. Gently prise the spring bars from the case lugs using the tool, then remove the old strap. Insert the spring bars into the new strap, aligning the ends correctly, then press until you hear a click. If you lack experience, consult a horologist: the procedure is straightforward but requires precision to avoid damaging the spring bars or the case.

Is a quality aftermarket strap compatible with the Day-Date 36 128239-0023?

Yes, entirely. The Rolex Day-Date 36 uses a universal attachment system with spring bars spaced 20 millimetres apart. Any artisanal strap constructed to horological dimensional standards is compatible. Casati Milano, for instance, manufactures 20mm straps made to measure that fit your Day-Date perfectly, offering the same reliability as official Rolex straps with greater chromatic variety and material options.

How long does a leather strap last on a daily-worn Rolex?

Durability depends on leather quality and intensity of use. Excellent alligator resists 3-5 years of daily wear before replacement becomes necessary. Vegetable-tanned calf typically lasts 2-3 years but continues to age elegantly during this period. Rubber and NATO are more resilient, often exceeding 5-7 years. Strap replacement is not a defect but a natural part of ownership: this is why Casati Milano offers an 18-month warranty against manufacturing defects, not natural wear.

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