CHANGE OF SEASONS

Gisborne Herald, Volume LXVI, Issue 20049, 22 September 1939, Page 12

CHANGE OF SEASONS

THE SPRING EQUINOX OCCURRENCE ON SUNDAY. The spring equinox will occur this vear on Sunday, on which day the sun will be vertical over the equator, and day and night, expressed in apparent solar time, will be equal all over the world.

For New Zealanders, as for ail other countries in the Southern Hemisphere, the equinox will mark the first day of spring, for the sun is steadily moving southward, daily rising higher in our skies and bringing greater warmth. The arbitrary selection of the September cciuinox as the first day ot spring is, however, merely a calendar convenience. Perhaps in no part of the world docs the aribtrary season so defined agree exactly with the meteorological season of the same name. In New Zealand, for example, the meteorological seasons begin generally some two weeks prior to the calendar seasons, but they vary from year to year, and their exact commencement cannot be determined until much later. Thus the adjacent equinox becomes the official first day of spring in the minds of the people, if not in those of the meteorologists.

The equinox, contrary to a widelyheld belief, does not always fall on the same date. Although generally referred to as falling on the 21st or 22nd day of the month, it may fall later, occurring this year on the 24th. New Zealand time, and on the 23rd in Greenwich time reckoning. It cannot. however, fail later than the 24th.