Hi DAZZA501 - we didn't post the NATION tournament in the calendar with all the other tournaments running this month because it's for NATION members only, and a lot of players aren't in the NATION. So, it could potentially cause a lot of disappointment for players who see it in the calendar and try to enter, but can't play due to eligibility.
Discussing with the team here right now....we will explore additional ways to better communicate NATION tournaments. Currently, we've been using email and the pop-up you see when you log in. We'll explore further how we can better communicate in the Forums and Tournaments page to NATION members only.