"Extended" POSIX time zone string?

Future transitions in a zone such as America/Godthab can't be represented by a POSIX time zone string. Transitions could be represented by a string such as... WGT-3WGST,M3.5.0/1u,M10.5.0/1u ...where the "1u" is an indication that transitions occur at 1:00 a.m. Universal time. Is this format extension (or something better) worth suggestion to the POSIX powers? --ado