楼主,可以的,摘自官网,就看你能不能受得了那改签费+差价
Q:How can I change the flight date of my tickets?
A: You can contact our call centre to make a change on date/time. A change fee of HKD$580 will be charged for every change on a per guest and per flight basis. Also, you may have to pay for any applicable fare difference; there will not be any refunds for lower fares. You can make the change up to 48 hours before scheduled flight departure. You may visit the page of Fees for more information.