ezic_zone:next/3 was not filtering the Zones to only those after UTCFrom. This may have caused an endless loop, always returning the earliest zone regardless of the progress of time. I wont know; I caught it rather early.
calling ezic:load("/path/to/tzdata_folder") returns a list of records without erroring-out.
The content may not be accurate; @todo create accuracy tests (idea: use system's zic/localtime/tzselect/etc.).