It seems unlikely that Easter Island changed from GMT-6 to GMT-7 for 4 hours (from 20 to 24) on 14 th. of March 1982, and then switched back to GMT-6. Rather it is more likely they stayed on the same time, by changing from one rule to another on 13.th of March at 21:00, which results in no time change at all on 13.th. or 14.th. of March in Easter Island. I don't know if this is something zic mends, but at least the Jodatime java package which uses the tz data directly, reflects this double DST change in their extracted data files, while Jodatime handles gracefully (zic-like) the hiccups of this type that only lasts for an hour (for instance the Knox Indiana change that was discussed earlier). Old rule: -7:00 Chile EAS%sT 1982 Mar 14 # Easter I Time -6:00 Chile EAS%sT New rule: -7:00 Chile EAS%sT 1982 Mar 13 21:00 # Easter I Time -6:00 Chile EAS%sT Regards, - Jesper Jesper Nørgaard Welen Email: jnorgard@Prodigy.Net.mx Project Leader (Líder de Proyecto) Software CIMMYT - Centro Internacional de Mejoramiento de Maíz y Trigo Dirección: CIMMYT Int. c/o Jesper Nørgaard Km. 45, Carretera México-Veracruz El Batán Texcoco, Edo. de México CP 56130 MEXICO Tel.: +52 (55) 58-04-20-04 ext. 1374 Fax: +52 (55) 58-04-75-58 Tel. Casa: 53-10-05-95 ó 53-10-97-78 Download the free program World Time Explorer, I made: http://www.cimmyt.org/timezone/index.htm