When was the man originally planning to leave for Las Vegas?

M: I would like to make a reservation for a flight to Las Vegas for March 8th.
W: Sorry, but all flights to Las Vegas are fully booked on March 8th. Actually, our flights to Las Vegas are all booked up through May 12th. It’ s the spring break season, you know. There are some business class seats available for the morning of March 9th.
M: That’ s too bad. Could you put my name on the waiting list on both March 8th and 9th? I have to attend a conference in the afternoon of March 9th.  By the way, how much is the business class?
W:  $320 dollars, sir. It’ s twice as expensive as an economy seat.