Brian Inglis wrote:
Perhaps we need to flag the initial LMT offset in each zone, whether specified or linked, rather than explicitly specifying it
That would be good if we were designing the format now, but the problem is backwards compatibility with all the existing systems out there. One possible way around this would be to say that the initial offset is flagged if its abbreviation is "LMT". In this case, which is typical, an application can safely ignore the offset in favor of any better information that it has, such as geographical coordinates. This would bless existing practice and wouldn't require changes to the code or data, though the documentation would need to be changed. (In the current database "LMT" also stands for "Lima Mean Time" and for "Lisbon Mean Time" but these aren't initial offsets -- see Europe/Lisbon and America/Lima.)