When the dust settled on Ben Shelton’s shock win over defending champion Carlos Alcaraz at 3:33 a.m. on Wednesday in the latest-ever finish at the U.S. Open, organizers faced a question that had been forming for days: how late is too late?

The concern was not sparked by one marathon alone as three matches ended after 2 a.m. during the Grand Slam’s opening week, while two more ran well beyond midnight, and Venus Williams was involved in the latest-starting clash that began at 12:13 a.m.

“Yeah, it’s not ideal,” the 46-year-old Williams said after losing to Sofia Kenin in the first round. “I would have preferred something else definitely.?