I'm not sure if there exists a rule that the tzdata files should use the capital of a country as base e.g. "Europe/Copenhagen" when there is only one time zone in a country. However, if that is the convention which is followed, it might interest you that Nigeria apparently changed capital in 1991 from Lagos to Abuja. My best source (there are plenty) is http://www.usia.gov/regional/af/sectrp99/infonige.htm which mentions the date for the capital change as being 12.th. of December 1991: ===== quote ======== Capital: Abuja note: on 12 December 1991 the capital was officially moved from Lagos to Abuja; many government offices remain in Lagos pending completion of facilities in Abuja. ===== unquote ======== Regards, Jesper Nørgaard Email: jnorgard@df1.telmex.net.mx Programador/Analista CIMMYT - Centro Internacional de Mejoramiento de Maíz y Trigo Dirección: CIMMYT, Lisboa 27, 06600 Mexico, D.F. Tel.: +52 (5) 7267541 ext. 1374 Fax: +52 (5) 7267558 Tel. Casa: 53-10-05-95 ó 53-10-97-78 CIMMYT home page: http://www.cimmyt.mx