Strap for Day-Date 36 White Gold Fluted / Oyster / Lapis Lazuli

The lug width of the Day-Date 36 reference 118239-0279 is 20 millimetres. This dimension must be measured between the internal attachment points of the spring bar, not across the external width of the spring bar housing. The permissible tolerance is maximum 0.5 mm to ensure the strap passage sits correctly without excessive play or oscillation.

For a Day-Date 36 118239-0279 in white gold, Nile crocodile leather is the historical and ideal choice: its regular granular structure does not distract from the case's elegance. Notable alternatives include vegetable-tanned calf leather, which develops a natural patina over time, and smoked shell cordovan from horse hide, appreciated for its durability and character development. Rubber remains an unconventional choice, recommended only to those who fully understand their personal aesthetic.

Changing the strap on a 118239-0279 requires extraction of the spring bar using a dedicated tool called a spring bar tool. Position the watch on a stable surface with the case back facing upward. Insert the tool into the spring bar slot, apply downward pressure whilst simultaneously lifting the lug: the spring will retract allowing disengagement. Repeat from the opposite end. The operation is swift if executed with care; avoid sharp blows that could scratch the case. We recommend entrusting the operation to a professional if you lack experience.

Yes, any strap with a 20 mm lug width is compatible with the 118239-0279. However, not all aftermarket straps meet the geometric tolerances necessary for perfect fitment. The strap passages must be correctly shaped around the case without creating voids or compressing the metal. Atelier Casati Milano manufactures bespoke straps specifically calibrated for this model, ensuring absolute compatibility and longevity.

A high-quality artisanal leather strap, worn daily, has an average lifespan of 3 to 5 years. Variables such as humidity, perspiration, sun exposure, and frequency of wear influence this estimate. Vegetable-tanned leather tends to last longer than rapid industrial tannages. Shell cordovan is particularly resilient and can exceed 7-8 years. Casati Milano's 18-month warranty covers manufacturing defects, not natural wear. Regular maintenance—gentle cleaning and seasonal protective treatments—significantly extends the strap's lifespan.