Strap for Day-Date 36 Yellow Gold Diamonds / President Diamonds / Black Diamonds Rubies

The lug width of the Rolex Day-Date 36 reference 118388-0123 is precisely 20 millimetres. This dimension represents the horizontal distance between the two lugs soldered to the case at the 12 and 6 o'clock positions, and is critical for the compatibility of any replacement strap. Verifying this measurement is essential before any purchase, as straps designed for other widths will not fit correctly into the case lugs.

Alligator leather in dark brown with a matte finish is the most recommended option: the scale pattern is finer than crocodile, the patina ages uniformly over time, and the aesthetic remains formal even after years of wear. Dark brown alligator paired with yellow gold represents the institutional choice par excellence. Valid alternatives include grained calf for a more contemporary style, or vegetable-tanned leather for those preferring sustainable materials that develop honey tones with age.

The procedure requires a specific tool called a spring bar tool and a stable work surface. Position the watch on a soft cloth with the case facing upward. Insert the flat tip of the spring bar tool into the small lateral hole of each lug at 12 o'clock, compress the internal spring, and extract the pin from the case. Repeat at 6 o'clock. Once the pins are free, remove the old strap and install the new one by reversing the process. If unsure about the procedure, it is advisable to contact a certified watchmaking workshop.

No. The 20-millimetre lug width is specific to the Day-Date 36 and certain Datejust models of the same generation. Straps designed for this width will not be compatible with Rolex models employing different lug widths, such as the Submariner (generally 20-22mm depending on generation), the Oyster Perpetual 36 (20mm), or the GMT-Master II (20mm in recent versions). Verifying the strap's lug width against the case is fundamental before any purchase.

The longevity of a leather strap depends on the material, frequency of wear, and environmental conditions. An alligator strap worn daily maintains optimal structural functionality for 3–5 years before showing visible signs of wear at the buckle or seam points. Shell cordovan, owing to its natural density, can last 5–7 years or longer. Calf leather, more delicate, performs better with less frequent wear and in controlled environments, developing a visually desirable patina within 2–3 years. Proper maintenance—avoiding prolonged exposure to moisture and UV rays, regularly cleaning with a soft cloth—significantly extends the functional and aesthetic lifespan of the strap.