Successful interview

Interviewer at a reputed business school said to the student “I shall either ask you ten easy questions or one really difficult question.

Think well before you make up your mind!”
The student thought for a
while and answered, “I would like to answer one really difficult question.”

“Well, good luck to you, you have made your own choice! Now tell me this.
“What comes first, Day or Night?”
The student was jolted into reality as his admission depends on the correctness of his answer, but he thought for a while and said, “It’s the DAY sir!”
“How?” the interviewer asked,

What did the student answer?