I had a booking on last Friday 13 Dec’s CX 364 17:30 departure HKG to PVG.

I was driving from Macau on the HKZM Bridge at 13:00, and realized that I could probably make it to the airport for the CX 380 departure at 15:00. I called 27473333 from my car. I was on a flexible ticket, so the Agent said there was no problem to change to the earlier flight without change fee, and there were seats available. However, he could not make the actual change for me, since that flight was under Airport Control (or something like that), but said he would remark on my PNR and told me just to approach the check-in desk. He also suggested anyway that, even if he could make the change, he not do it because that would make me lose my seat on CX 364 (that flight was full), and if there were any delays in my getting to the airport and could not catch CX 380, I would no longer have the seat on CX 364. Made a lot of sense to me, so I followed his advice.

I got to HK Airport with plenty of time to spare, and First check-in made the change to the earlier flight for me.