He dies when hit by his own curse in the Great Hall, the climax of the Battle of Hogwarts. (DH36)
He dies just at sunrise, when the sun's rays come through the windows of the Great Hall. Sunrise on 2 May in Scotland is at 5:32 AM.
The Death of Voldemort
Date May 2nd, 1998
Certainty Stated in canon
Location in Canon DH36: The Flaw in the Plan
Type of Event Wizarding world