Big Brother's Season 21 premiere date has been announced by CBS. The network has announced Season 21 of Big Brother will return with a two-night premiere event on Tuesday, June 25 and Wednesday, June 26, with both episodes airing from 8-9PM ET\/PT. RELATED LINK: 'BIG BROTHER' SHOWMANCES NOW: WHO'S STILL TOGETHER? WHICH COUPLES HAVE SPLIT UP?? (PHOTOS) Big Brother will continue to air three episodes every week this year. Following the first two episodes of the new season, Big Brother will air a one-hour broadcast on Sunday, June 30 at 8PM ET\/PT on CBS. Beginning on Wednesday, July 10, the show will move to Wednesday and Thursday nights from 9-10PM ET\/PT. The Sunday night broadcast, however, will remain in its 8PM ET\/PT timeslot once the schedule changes in July. Big Brother will continue to be hosted by Julie Chen. Big Brother follows a group of strangers living together in a house together that's outfitted with 94 HD cameras and more than 113 microphones, recording their every move 24 hours a day. Each week, someone will be voted out of the house, and the last houseguest remaining will win the grand prize of $500,000. Last season, Kaycee Clark was crowned champion of Big Brother, defeating runner-up Tyler Crispen in the jury vote. RELATED LINK: 'SURVIVOR' COUPLES NOW: WHO'S STILL TOGETHER?! WHICH SHOWMANCES SPLIT UP? (PHOTOS) Big Brother is produced by Allison Grodner and Rich Meehan for Fly on the Wall Entertainment, in association with Endemol Shine North America.