The precedent that is most relevant is here: https://caselaw.findlaw.com/court/us...t/1638039.html. Session appears 17 times in the opinion.

Unless the bill changes current law, the burden of proof is always with the taxpayer, not the IRS.

Quote Originally Posted by Dan Druff View Post
Quote Originally Posted by mickeycrimm View Post
There HAVE BEEN court rulings against claiming an entire year for a session. I'll see if I can dig them out. Some gamblers have been defining a 3 or 4 day gambling trip as a session for several years now and the IRS hasn't fired them up.
Yes, dig them up if you can.

What's the longest "session" that has been upheld by the IRS?