I went through last year's thread. It looks like Stanford trickled out invitations until Monday, November 16th. That whole week they sent out the bulk of their invitations, it seems. The following week, nothing (thanksgiving), and the beginning of the next week (first week of dec) it seems like there was a smaller burst.
This year may not look like last year, but if it did, that would put the flood gates opening on November 15th up until November 19th.
I'm really only posting this so that people don't stress over things too much... maybe there will be an invite or two starting next week (that's when this board got actual posts about invitations being received although only a couple of those), but no worrying until November 20th, please!