Info about tz database data storage in Wikipedia can be found at ((Time zone/doc#tz database)).
This template stores data that might be usable by ((coord)). (It's unclear what this means - the coord template needs separate params (i.e. '|'-separated). Not sure why the original author chose this '/'-separated format. TBD). Used by ((Infobox IANA time zone)).
Template:Time zone/coordinates contains the coordinates in the original format.