Strap for Day-Date 36 White Gold / Oyster / Cherry

The lug width (ansa width) of the Day-Date 36 118239-0304 is precisely 20 millimetres. This is a specific dimension requiring a strap with 20 mm compatible lugs. To verify correctly, insert a digital calliper between the two lugs of the case, measuring the internal distance, which should read 20 mm.

Alligator leather with vegetable tanning is the optimal aesthetic choice, as its natural geometric texture dialogues perfectly with the white gold case and develops a noble patina over time. Alternatively, box calf offers elegance with greater chromatic stability, whilst shell cordovan provides superior abrasion resistance. All options require a double-push deployante to preserve case integrity over the long term.

Remove the watch from your wrist and position it with the caseback facing upward. Use a springbar tool to gently compress the lug spring towards the case centre, apply leverage, and slide the lug out of the hole. Repeat for both sides. During installation, insert the lug into the case hole, ensuring the spring positions correctly, then push until you hear the locking click. Never force: incorrect movement may damage the lug attachments.

Yes, provided the strap is specifically compatible with the 20 mm lug width and the case lugs are intact. A high-quality artisan strap, crafted with selected leathers and professional stitching, offers aesthetic personalisation while maintaining original functionality. Casati Milano produces bespoke 20 mm straps designed specifically for the Day-Date 36.

A quality artisan alligator or calf leather strap maintains structural functionality for 8-12 years with regular maintenance (cleaning with a damp cloth, rapid drying, annual conditioning with dedicated creams). The patina evolves over time, imparting character. Shell cordovan, being more abrasion-resistant, may achieve slightly longer lifespan. Environmental factors (humidity, sun exposure, perspiration) accelerate the natural ageing of leather but do not compromise mounting security if stitching remains intact.