Rolex · Day-Date 36

Strap for Day-Date 36 White Gold / Strap / Blue

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
Reference118139-0026
FamilyDay-Date 36
MovementRolex caliber 3155 hours, minutes, seconds | date, day | chronometer
Year2017
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 118139-0026

Selected for the 20 mm lug width · workshop selection

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The Day-Date 36 118139-0026, seen from the bench

The Day-Date was introduced in 1955 as the first wristwatch to indicate the day and date in full. It mounts the automatic Caliber 3155 with official chronometer certification. 36mm white gold case with 20mm lugs and integrated President bracelet.

Frequently asked questions

What is the lug width of the Rolex Day-Date 36 118139-0026?

The lug width of the Rolex Day-Date 36 reference 118139-0026 is 20 mm. This measurement is taken between the two lugs at the point where the strap attaches to the case, and it is consistent across all production examples of this white gold 36 mm reference.

What is the best strap for the Rolex Day-Date 36 118139-0026?

For the Day-Date 36 in white gold, a belly-cut alligator strap — in gloss black or tobacco brown — is the canonical choice, as the scale texture complements the case finishing. Shell cordovan offers a dense, structured patina well suited to extended formal wear. In all cases, the 20 mm strap must feature curved ends to conform correctly to the geometry of the integrated lugs.

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

Changing the strap on a Rolex Day-Date 36 requires a fine-tipped springbar tool to compress the springbars housed within the integrated lugs. It is advisable to work on a soft watchmaker's mat to protect the bezel and dial. If you are not experienced with this procedure, we recommend entrusting the work to a watchmaker or to Casati Milano's atelier to avoid scratching the white gold case.

Are there aftermarket straps compatible with the Rolex Day-Date 36 118139-0026?

Yes. Aftermarket straps compatible with the Rolex Day-Date 36 118139-0026 must conform to the 20 mm lug width and feature pre-curved ends to fit the integrated lugs correctly. Milanostraps.it offers a curated selection of handcrafted 20 mm straps in alligator, calf leather and shell cordovan, with buckle or deployant clasp options available in various metals, including white gold PVD finish.

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

The lifespan of a leather strap depends on the material, care and frequency of use. A quality alligator strap worn daily typically lasts between two and four years before visible wear appears on the keeper and inner lining. Shell cordovan, owing to its structural density, tends to last longer whilst developing a distinctive patina. Avoiding prolonged exposure to water and perspiration will significantly extend the strap's service life.

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