The multi-day later is a custom CLOT with multiple templates, a better rating system, and more statistics! It even comes with it's own golden trophy!
You can veto up to 7 templates, contribute to clan statistics, or even play up to 9 games rather than the normal 5.
To join, click the link above, and hit the login button, once redirected to warzone, click "Proceed" and then Join when back onto the clot site.
If you're on mobile and clicking the buttons is giving you problems, I suggest clicking desktop site in your browser settings. That makes it work for me.
If you're not sure what a CLOT is, check https://www.warzone.com/wiki/CLOT