Details on the third debate, from here:

• Each debate will be broadcast live on C-SPAN, ABC, CBS, FOX and NBC, as well as all cable news channels including CNN, Fox News and MSNBC among others.
• The debates will air from 9pm to 10:30pm ET (8pm – 9:30pm CT, 7pm – 8:30pm MT, 6pm – 7:30pm PT)

Wednesday, October 19, 2016
Third presidential debate
Moderator: Chris Wallace, Anchor, Fox News Sunday
Location: University of Nevada, Las Vegas, Las Vegas, NV

The format for the third debate will be identical to the first presidential debate.