<p>“Is there an official start day, and the classes simply start up on the next corresponding date?.” This.</p>
<p>I don’t know where you are getting that your discussions are on Monday and Wednesday unless you are looking at EEE because it will tell you WHICH days of the week you will have class, it doesn’t necessarily say WHEN they first start. </p>
<p>Classes officially start on the 23rd. You may or may not have class that day depending on your professor, but the safest way to go about this is to go to all your classes on Thursday (23) unless your professors sends you an email saying there is no class or discussion.</p>