We check each Nation's Victory Points two weeks (336 hours) after a Conquest Cycle begins and then once a week (every 169 hours) after that. If during this Victory Check any Nation has at least 300 points, then we declare that Nation the winner.
To see when the next check will be, on the Toolbar, click the Conquest button (or press R). The Conquest window will open. At the top of this window, you will see a message similar to "Next update in 3 days." Meaning, in 3 days we will check to see if any Nation has won this Conquest Cycle.