Question about Enewetak

Hi! On many places in the Internet I find pages that tell that Enewetak on the Marshall Islands has an offset vs. Greenwich Meantime of -12 hours, but the tz data base states +12 hours (for all Islands of the Marshalls). What is correct? The named pages all tell, that Enewetak is different to the rest of the Marshall Islands. Can it be, that this Island was one of these to change date before the year 2000 to be the first to celebrate it? If not, is there something missing in the tz database? Thanks a lot in advance, Dani