CBS has unveiled that “ Big Brother ” Season 28 premieres on July 9 at 8 p.m. ET/PT. The show’s companion series, “Big Brother: Unlocked,” returns the following day in the same time slot. After the Season 28 premiere, subsequent episodes will air Wednesdays and Thursdays at 8 p.m. ET/PT, while the live evictions will be on Sundays at 8 p.m. ET/PT. CBS promises “Big Brother” Season 28 will feature “the most programming hours ever.” The show will also debut its 1,000th episode during the new season. According to CBS, “Big Brother” is the first primetime series to cross the milestone. The two-hour Season 27 finale pulled in the reality competition series’ biggest audience in more than three years, reaching an average of 4.3 million views on CBS . According to Nielsen, it was a 33% jump from the Season 26 premiere, which reached 3.2 million viewers. 25-year-old Chicago native Ashley Hollis was the “Big Brother” Season 27 winner. She defeated runner-up Vince Panaro in a 6-1 jury vote and took home $750,000.…