Hi there!
Vigilant is an Alliance guild on Sargeras. We have two teams, both teams having cleared Mythic in past tiers. I am specifically representing the weekend team which raids Sat/Sun 8-11PM CST. We are seeking skilled players such as yourself so that we can continue to push our team towards cutting edge in a fun, more laid back but still structured environment. I have included our forum post below with more information, including our guild website.
Our times line up with your requirement of 9-12PM EST, just on the weekend. Feel free to reach out to me with questions if this interests you. I have sent you a btag request from MightyMal#1583 so that you know who that is. Best of luck in your search and welcome back to the game.
Remain ever Vigilant.
Unholy