Rotating Game Queue

So patch notes are out, and i was wondering about the rotating game mode. It says 4pm server time is when it will start. But seeing as servers are spanning multiple time zones, Which time zones is server? Do Eastern players get screwed by a later start? Do western players get screwed by a later ending?

For reference, Riot is based in California, Servers are in Chicago and the most eastern time zone is Atlantic (Canada only mind you)

This applies to Europe as well, I'm just from NA