Turks & Caicos switched to U.S. DST dates?

On 2007-03-15 Chris Dunn reported to the Debian bug list that the Turks & Caicos Islands (America/Grand_Turk) changed their DST transition dates this year to match the U.S. dates; see Debian bug 415007 <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=415007>. He made no mention of the time, so I guess we should continue to assume transitions at 00:00 local time. It'd be nice if someone could confirm this with a more-authoritative source.