Sunday will be the busiest post-Christmas travel day at Denver International Airport. Officials say they're expecting more than 200-thousand people to pass through the gates. Travelers flying out of DIA are being advised to arrive inside the terminal two hours before their scheduled departure time. More than two-point-five-million passengers were forecasted to travel through the airport from December 20th through January 2nd. That's about a four-percent increase over the same time last year.