Rolex · Day-Date 40

Strap for Day-Date 40 Platinum - Baguette / Black Baguette

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

Lug width20 mm
Case diameter40 mm
Reference228396tbr-0012
FamilyDay-Date 40
MovementRolex caliber 3255 Hours, Minutes, Seconds | Date, Day | Chronometer
CasePlatinum

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 40 228396tbr-0012

Selected for the 20 mm lug width · workshop selection

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The Day-Date 40 228396tbr-0012, seen from the bench

The Day-Date was introduced by Rolex in 1956 as the first wristwatch to display both the day and date in full. The Day-Date 40 version is equipped with the automatic Caliber 3255 with chronometer certification, indicating hours, minutes, seconds, date and day of the week. 20mm lugs complete the case construction.

Frequently asked questions

What is the lug width of the Rolex Day-Date 40 228396tbr-0012?

The lug width of the Rolex Day-Date 40 228396tbr-0012 is 20 mm, measured perpendicularly from inside edge to inside edge of the lateral case lug. This dimension is critical for purchasing a compatible aftermarket strap.

What is the best strap for the Rolex Day-Date 40 228396tbr-0012?

For this platinum reference, Nile alligator with traditional tanning represents the most coherent aesthetic choice. The leather with uniform geometric scales maintains the British formalism parallel to the watch's design. Vegetable-tanned calf leather is an excellent alternative for those who appreciate colour evolution over time.

How do you change the strap on a Rolex Day-Date 40?

Use a dedicated spring bar tool. Position the watch face-down, insert the tool into the lateral bar slot, lift gently and slide the bar outward. Repeat on the opposite side. Reverse the procedure for the new strap, ensuring the bar is properly seated in both lug holes.

Can an aftermarket compatible strap be used on this reference?

Yes. The strap must be precisely 20 mm in width, with connecting bars in stainless steel or platinum. Verify that total length accommodates your wrist and that the deployant functions correctly. Italian artisanal straps with manufacturing guarantees are recommended.

How long does a leather strap last on this Rolex?

With moderate daily use and appropriate maintenance, an alligator strap lasts 4-6 years before replacement. Vegetable-tanned calf shows better longevity if protected from excessive moisture (6-8 years). Durability depends on sun exposure, perspiration, frequency of use and preventive care.

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