Rolex Day-Date: The Original History of the President’s Watch Posted on Jun 17, 2016Mar 15, 2018 Author Luca Musumeci Rolex’s 6611 models that were waterproof up to 100 feet soon replaced the Day Date but it was still externally identical to the 6611. The 6611 featured the new caliber 1055 movement with its free sprung Micro-Stella balance, the firs...