(a) The northern boundary of the Southern Winter Seasonal Zone is the rhumb line from the east coast of the American continent at Cape Tres Puntas to the point latitude 34° S., longitude 50° W.; thence the parallel of latitude 34° S. to longitude 17° E.; thence the rhumb line to the point latitude 35°10′ S., longitude 20° E.; thence the rhumb line to the point latitude 34° S. longitude 28° E.; thence along the rhumb line to the point latitude 35°30′ S., longitude 118° E.; thence the rhumb line to Cape Grim on the northwest coast of Tasmania; thence along the north and east coasts of Tasmania to the southernmost point of Bruny Island; thence the rhumb line to Black Rock Point on Stewart Island; thence the rhumb line to the point latitude 47° S., longitude 170° E.; thence along the rhumb line to the point latitude 33° S., longitude 170° W.; and thence the parallel of latitude 33° S. to the west coast of the American continent.

(1) Valparaiso is to be considered as being on the boundary line of the Summer and the Winter Seasonal Zones.

(2) Seasonal periods:

[CGFR 68-60, 33 FR 10068, July 12, 1968]