I suggest a few additions to the links on the twinsun time zone page http://www.twinsun.com/tz/tz-link.htm Starting last December the ITU-R has provided free online access to their recommendations. These are visible at http://www.itu.int/pub/R-REC It is a major change from the previous restrictions on ITU-R documents. This includes the time and frequency recommendations http://www.itu.int/rec/R-REC-TF/en some of which are now suppressed but which describe the history of the usage and nomenclature. In particular it has the current and two previous versions of ITU-R TF.460 which is the document that describes radio broadcast time signals and UTC. http://www.itu.int/rec/R-REC-TF.460/en The earlier versions document the connections between UTC and GMT. There are many other possibly relevant sources, but these have been deemed particularly important and they are the basis for the inputs that go to the zoneinfo database and code. -- Steve Allen <sla@ucolick.org> WGS-84 (GPS) UCO/Lick Observatory--ISB Natural Sciences II, Room 165 Lat +36.99855 1156 High Street Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m