world times zone

Hi,

has anyone ever work with  timezone.cfc ?  there is the functinon getTZOffset that i am quite to understand where can i get timezone ids?

<cfset variables.tzList = listsort(arrayToList(variables.tzObj.getAvailableIDs()), "textnocase")>

what is textnocase?

i found something like this for Poland but don't know what is CET? and where i can find this information?

tz.getTZOffset(today,'CET');

samething for PRC=tz.getTZOffset(today,'PRC');  PRC?

Thanks