The HBO boxing schedule for upcoming fights is available in the sports section of the HBO website. Each upcoming fight has its own area listing the time and date of the fight, the boxers involved, and a shortened "Tale of the Tape" for each boxing match.
The "Tale of the Tape" found on HBO boxing refers to an individual boxer's attributes and typically includes a win/loss record, the boxer's hometown and height. After the official weigh-in for each boxing match, the "Tale of the Tape" also includes the weight of the boxer and his reach as measured from his armpit to the end of his fist.
BoxingScene.com has a page devoted to upcoming HBO fights in its schedule section. Information for each fight includes the location of the fight, the fights on the under card of the main event and whether a title belt is to be won in each contest.
FightNights.com also has a section devoted to the upcoming HBO boxing matches in its schedule area. This website also includes the under card for each fight along with more information such as the "Tale of the Tape" for every fight and the number of rounds scheduled for each fight.