Jon Skeet wrote:
in Noda Time I could probably support non-infinite rules with a fixed set of types (hopefully just odd and even), but it would be a bit of work. If type values are effectively obsolete, I may not bother.
As far as I know, these haven't been used for some time in tzdata. They do not work with Fedora 21 port of zic, or with Ubuntu 15.04's port, because Fedora and Ubuntu do not install the 'yearistype' command. They mostly work in Solaris, but only because Solaris modifies zic.c by hardcoding the special values "even", "odd", "uspres" and "nonpres". If we wanted to support these values portably, I imagine we'd have to implement them the Solaris way. Instead, how about if we document them as obsolescent, as in the attached proposed patch? We needn't change the implementation, so that the obsolete usage should continue to work on whatever platforms install yearistype.