Thanks for the heads-up. I've pushed this patch to the experimental repository:
From f0b7563dc269b34593a1667845530f525a731e8b Mon Sep 17 00:00:00 2001 From: Paul Eggert <eggert@cs.ucla.edu> Date: Wed, 13 Nov 2013 01:00:16 -0800 Subject: [PATCH] America/Havana: fix spring 2004 transition
* northamerica (Cuba), NEWS: In 2004, Cuba began DST on March 28, not April 4. (Thanks to Steffen Thorsen.) --- NEWS | 5 +++++ northamerica | 8 +++++++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/NEWS b/NEWS index 246abcd..0734458 100644 --- a/NEWS +++ b/NEWS @@ -2,6 +2,11 @@ News for the tz database Unreleased, experimental changes + Changes affecting past time stamps: + + In 2004, Cuba began DST on March 28, not April 4. + (Thanks to Steffen Thorsen.) + Changes affecting code The compile-time flag NOSOLAR has been removed, as nowadays the diff --git a/northamerica b/northamerica index c3921d3..83c521b 100644 --- a/northamerica +++ b/northamerica @@ -2665,6 +2665,11 @@ Zone America/Costa_Rica -5:36:13 - LMT 1890 # San Jose # to DST--and one more hour on 1999-04-04--when the announcers will have # returned to Baltimore, which switches on that date.) +# From Steffen Thorsen (2013-11-11): +# DST start in Cuba in 2004 ... does not follow the same rules as the +# years before. The correct date should be Sunday 2004-03-28 00:00 ... +# https://web.archive.org/web/20040402060750/http://www.granma.cu/espanol/2004... + # From Evert van der Veer via Steffen Thorsen (2004-10-28): # Cuba is not going back to standard time this year. # From Paul Eggert (2006-03-22): @@ -2854,7 +2859,8 @@ Rule Cuba 1996 only - Oct 6 0:00s 0 S Rule Cuba 1997 only - Oct 12 0:00s 0 S Rule Cuba 1998 1999 - Mar lastSun 0:00s 1:00 D Rule Cuba 1998 2003 - Oct lastSun 0:00s 0 S -Rule Cuba 2000 2004 - Apr Sun>=1 0:00s 1:00 D +Rule Cuba 2000 2003 - Apr Sun>=1 0:00s 1:00 D +Rule Cuba 2004 only - Mar lastSun 0:00s 1:00 D Rule Cuba 2006 2010 - Oct lastSun 0:00s 0 S Rule Cuba 2007 only - Mar Sun>=8 0:00s 1:00 D Rule Cuba 2008 only - Mar Sun>=15 0:00s 1:00 D -- 1.8.3.1