"Jonas Melian" <jonas.esp@googlemail.com> writes:
It contains a two-letter code which is recommended as the general purpose code, _a three-letter code which has better mnenomic properties_
But that part of the TZ database is not intended for end-users. It is intended for internal processing. So its mnemonic properties are not that relevant. I just now ran my host's time zone setup tool. (I'm running Debian stable, a fairly old GNU/Linux distribution.) The tool gave me a map of the world with cities and islands scattered over it, along with a list of text time zone names like "America/La_Paz". Nowhere did it use two-letter codes. If my experience is typical, changing from two-letter codes to three-letter codes would not help typical users. It would affect only developers. But most developers, I think, would prefer two-letter codes, even if were no cost to switching th three-letter codes. They're more familiar with the two-letter codes, due to their widespread use in Internet domain names. There's a nonzero cost to switching. Existing software reads zone.tab and iso3166.tab and expects these files to have a certain format. To switch, we need a compelling technical reason. So far, I haven't seen one.