As it stands right now, the suggested new zone from Trần Ngọc Quân does not differ from Asia/Ho_Chi_Minh after 1970 and should not be added, per the Theory document, as Robert Elz alluded to. Whether a city is a capital or official legal basis for a time zone should not affect our nomenclature.

On 3 October 2014 06:39, Alan Barrett <apb@cequrux.com> wrote:

The Wikipedia page, <https://en.wikipedia.org/wiki/Time_in_Vietnam>, says that they were different.

I would note that that page only had one author and does not cite any sources relevant to the data it presents. The second and fourth sources provided in the proposed patch (in Vietnamese) don't seem to support its data; however, the third reference provided, http://www.thoigian.com.vn/?mPage=P80D01, seems somewhat promising, although I don't think it provides nearly as much specificity as the proposed patch.

For example, from 1968 to 1975, North Vietnam (Hanoi) was on UTC+07:00, and from 1960 to 1975, South Vietnam (Saigon, or Ho Chi Minh City) was on UTC+08:00.

If this is true, then Asia/Ho_Chi_Minh needs to be updated, in which case a new zone for North Vietnam is indeed needed to accurately reflect the pre-unification differences. Per Theory, this zone would probably be called Asia/Hanoi as "Hanoi" is more common in English than "Ha Noi".

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Tim Parenti