I have seen CX delaying its Surabaya flight from HKG by 11 hr 45 mins consistently over the past 2 weeks and further extend this pattern for the next 7 days, with all the official blame goes to volcano ash cloud. The new flight time is now at 3:15am and arrive Surabaya at 7am.

Here is the magic part. If the delay is due to ash cloud, it should have also affected the whole airport, but not only on CX flight. But SUB is operating normally and most flights arrive and depart within a reasonable time frame. Even CX's flight returning to HKG departs on time at 8:30am consistently.

Since my flight is on Feb 5, which is still officially unchanged as the delay notice only cover flights up to Feb 4. My frustration is whether I should cancel my hotel or reschedule.

I can't think of any solid reason of why this could happen except CX wants to take this opportunity to save cost. Since they are flying A340 on this route, they can also utilize the aircraft during that miserable 11:45 hr for a short haul round trip. If CX is considering changing the departure time permanently, they should just let us know.