I'm currently on a Multi-Entry Retirement Visa and am about to fly to the US. I am unsure whether I need to get a re-entry permit before going to the airport or not? The next two days are holidays - will the international terminals have someone staffed to take care of it for me at the airport? I'll be arriving at Suvannabhumi at 4am for a 7am flight - would the re-entry permit booth even be staffed at that hour anyway?