"We will decide what tomorrow brings when tomorrow comes," the Montgomery County, Pennsylvania, judge told jurors Friday.
Cosby's defense team has been asking for a mistrial, but Judge O'Neill says he's compelled by law to allow deliberations to continue as long as the jury wants.
Cosby, 79, is accused of sexually assaulting Andrea Constand in 2004. The jury is weighing three counts of aggravated indecent assault. Cosby, who says the sex was consensual, has pleaded not guilty in the Constand case and has repeatedly denied allegations of wrongdoing.
Cosby thanked his supporters as he exited the courthouse in Norristown Friday night.
"I just want to wish all of the fathers a Happy Father's Day," said Cosby, who also tweeted videos of his remarks. "And I want to thank the jury for their long days. Their honest work, individually. I also want to thank the supporters who have been here. And, please, to the supporters, stay calm. Do not argue with people. Just keep up the great support. Thank you."
Cosby also tweeted a video of supporters outside the courthouse chanting, "Let Bill go."