Markus G. Kuhn wrote:
I do not have very strong feelings about the optionality of the minute offset, but my arguments for it are:
- only *very* few countries use it today and time zones are so often redefined that there is some good hope that the 30-min offset zones will disappear in 2020 or so. Then, we would not carry around any more the obsolete minute fields in our headers.
- I personally think that the hour only offset is much more readable and that the additional implementation effort (one single "if" in my sample code) is so trivial that it is really not worth any discussion.
I would make minute offsets mandatory, because we are discussing not only contemporary but historical time zone data, when minute offsets were more common. Also IMHO minute offsets are not necessarily a Bad Thing; a small country without any of its territory going through an hourly meridian but with territory going through a minute offset might be better served by the minute offset zone; Portugal and Ireland, for example, fit GMT-0:30 closer than GMT or GMT-1. What I would favor is putting a colon in between hours and minutes, for readability; i.e. the time in Darwin, Australia is easier to read as GMT or UT+09:30 than as +0930. My $0.02 worth...