Strap for Day-Date 36 Yellow Gold Diamonds / Oyster / Green Paved

The lug width of the Day-Date 36 118388-0121 is 20 millimetres. This measurement is taken between the two spring bar attachments on the Oyster case. This specification remains consistent across all 36mm Oyster cases within the same design family, though larger models such as the 40mm variants may require different lug widths depending on their reference number.

For a yellow gold 18k Day-Date 36, we recommend natural alligator leather in dark brown (cognac) or deep black tones, which creates striking luminous contrast with the gold case. Alternatively, Italian calf leather with vegetable tanning in aged cognac enhances the natural patina of the gold. For daily versatility, Russian horse shell cordovan combines structural integrity with an internal lustre that develops through wear. All choices should maintain visual balance: 20mm lug width typically pairs best with leather thickness between 4 and 5 millimetres to preserve proportional aesthetics on the wrist.

Strap removal requires a professional spring bar removal tool (specialised screwdriver or dedicated pliers). Position the watch sideways, locate the micro-hole beneath each lug, insert the tool to compress the internal spring mechanism, and slide the lug outward. Repeat on the opposite side. To install the new strap, align the holes with the spring bars and insert until a secure 'click' confirms proper seating. We recommend entrusting this operation to a certified watchmaker to prevent damage to the gold case attachment points.

Yes, provided the strap is specifically designed for 20mm lugs. Technical compatibility depends on three parameters: lug width (exactly 20mm), internal spring bar hole diameter (1.80mm standard), and structural durability (for a gold case, we recommend leather thickness of at least 4mm). Specialist aftermarket manufacturers including Casati Milano observe these standards rigorously. Always verify with the vendor that compatibility is certified for your specific reference model.

A premium leather strap—whether alligator, calf, or shell cordovan—typically lasts between 3 and 7 years on a Day-Date 36, depending on frequency of wear and environmental exposure. Perspiration, humidity, and UV radiation reduce longevity; regular maintenance (gentle cleaning with a damp cloth, thorough drying, annual conditioning with specialist products) extends functional life significantly. A strap fitted with a steel deployant clasp experiences less structural stress at the lugs compared to a traditional buckle, potentially adding 1–2 years to overall durability. For a watch of this calibre, we recommend commissioning a skilled artisan to restore and redye a cherished strap rather than replacing it entirely when the leather begins to age.