 Candidates will make their pitch to voters less than five months before the election. Both have accepted the new rules and a new format for the 90-minute debate, which will not include a live audience. It requires that their microphones be muted when the other is speaking. Biden has been huddled at Camp David with top White House and campaign aides over the last few days holding mock debates. Meanwhile, Trump has held a series of private meetings with allies and has been on the campaign trail.