Expect the unexpected as Big Brother is set to return on Thursday, July 9, at 8 p.m. ET on CBS . Julie Chen Moonves will also return as host of the reality competition, with the season kicking off with a special 90-minute episode. Not only that, but the Sunday episode on July 12 will also be 90-minutes. Season 28 of Big Brother will achieve a historic feat: it will be the first series to reach 1,000 original episodes in primetime. The season ushers in a landmark summer as Houseguests enter the iconic Big Brother house with unexpected moments and a season packed with twists and turns. After its premiere, Big Brother will air on Wednesdays from 8 p.m. to 9:30 p.m. ET, followed by hour-long Thursday shows featuring the live evictions and Sundays at 8 p.m. ET. Watch on Deadline Also returning this summer is companion series Big Brother: Unlocked , which features exclusive footage from inside the house, extended interviews, surprise guest appearances, and behind-the-scenes access.…