It's official. As of 12:01 a.m. Sunday, TCU and West Virginia University are part of the Big 12 Conference.

At that same exact moment, founding Big 12 conference members Missouri and Texas A&M completed their move to the Southeastern Conference.

Sunday marks nearly seven months of preparation and in the case of WVU, a legal fight to separate from the Big East early.

"We are extremely proud to call TCU and West Virginia members of the Big 12 and welcome Horned Frog and Mountaineer students, faculty, staff and fans to the Conference," Big 12 commissioner Bob Bowslby said. "Both institutions bring with them academic and athletic credentials that advance the Conference's standing within intercollegiate athletics. I couldn't be more excited for the future of the Big 12 Conference."

TCU held a countdown celebration Saturday night at the historic Fort Worth Stockyards. It's a homecoming of sorts for the Horned Frogs. The move will allow TCU to rekindle the rivalries it had with Texas, Baylor, and Texas Tech in the Southwest Conference before it disbaned in 1996.

West Virginia will celebrate with a cookout in Morgantown on Sunday afternoon.

“July 1, 2012 is an important and historic day for our University,” Director of Athletics," Oliver Luck said. “We wanted to do something special for our student-athletes as we join the Big 12 Conference, and bringing them together along with our coaches and staff will be a great way to recognize our membership into a new league. Everyone has been looking forward to this day and Sunday will be a time to enjoy it as an entire department.”