Thank you for the response! What distance from shore defines "the territorial waters of any nation"? Is it nation specific, or an internationally recognized distance from shore? Thank you! Christina -----Original Message----- From: Paul Eggert [mailto:eggert@CS.UCLA.EDU] Sent: Thursday, June 21, 2007 12:56 PM To: tz@elsie.nci.nih.gov Cc: Christina Lawrence Subject: Re: TimeZones and international waters To help clear this up I'll add something like the following to my next proposed patch. Comments welcome. A ship within the territorial waters of any nation uses that nation's time. In international waters, time zone boundaries are meridians 15° apart, except that UTC−12 and UTC+12 are each 7.5° wide and are separated by the 180° meridian (not by the International Date Line, which is for land and territorial waters only). A captain can change ship's clocks any time after entering a new time zone; midnight changes are common.