<p>Does that mean I can send it on November 1st?</p>
<p>It needs to be processed by the USPS on November 1. Dropping it into a mailbox at 7:30PM won't get the November 1 postmark.</p>
<p>To ensure the postmark, you should hand it to a post office counter employee.</p>
<p>That being said, I can imagine that your target school isn't pouring into the dumpster every envelope that says "Nov 2".</p>