Little Saigon Tet Parade Brings South Vietnam Back To Life

The reason British and US has the same day of New Year, because both are using Gregorian calendar. British and US are celebrating in different way.

Yes, but you would never read in a paper "Americans in Boston celebrate Italian New Year."  Your reply that the Chinese created the notion of the Year of the Dragon also holds no water.  Pope Gregory created the current calendar, but you would never write, "Americans celebrate Catholic New Year."  Tet and Chinese New Year are often, although not always, on the same day, but that does not mean they are identical.  And in terms of practice and customs, Vietnamese New Year has many customs that are totally different than the Chinese New Year.  If Mr. Nguyen seemed irked, it's probably because there is a long history in this country of people thinking that all Asians are interchangeable.  There is also a tendency for uneducated people to use the term "Chinese" for anything East Asian. Slightly less obvious but almost as ignorantly, others have a misconception that Vietnam is some kind of cultural suburb of China - a misconception, incidentally, which led to many strategic errors during the Vietnam War.  As a citizen of the US, whose history is tragically interconnected with Vietnam, and also as a journalist, you could strive for basic accuracy.