In large cities, it is possible to pay for most luxury items with a credit card. TIME ZONE Thirteen hours ahead of Eastern Standard Time and seven hours ahead of Greenwich Mean Time, Vietnam is in the same time zone as Thailand, Laos, and Cambodia and one hour behind China and Hong Kong. Learn more about airfare deals to Asia at Vietnam Adventures , a Web site dedicated to Vietnam travel. Domestic flights are relatively expensive due to a heavy foreigner surcharge. The 900-mile train trip from Saigon to Hanoi takes 36 to 44 hours.
Local buses are inexpensive but very crowded.
The climate differs greatly between the southern, central, northern, and highland areas. Rain usually falls in heavy afternoon spurts, particularly from July to January. The central area is usually best to visit in February and March, but the weather can vary greatly from year to year. It is wet from May to January, particularly in October. Halong Bay, which is magnificent in the sunshine, looks rather ordinary on an overcast day.