Oh man..... I was on my phone in the evening and I noticed flights available from SGN to YWG ......so I then looked at HAN for the same route. I was so excited and thought I was so lucky. I told my wife and then went back in and everything was gone! I had not looked during the day so thought I missed out because I wasn't paying attention all day! Been steaming about it all day.............until I read this. It sounds like they were available for 12 hours - I literally must have been checking right at the bitter end of the evening.