Add arrays for south hemisphere seasons

documentation/almanac.rst

@@ -463,7 +463,8 @@ The result ``t`` will be an array of times, and ``y`` will be ``0``
 through ``3`` for the Vernal Equinox through the Winter Solstice.
 
 If you or some of your users live in the Southern Hemisphere,
-you can use the ``SEASON_EVENTS_NEUTRAL`` array.
+you can use the ``SEASON_EVENTS_SOUTH`` array.
+Alternatively you can use the ``SEASON_EVENTS_NEUTRAL`` array.
 Instead of naming specific seasons,
 it names the equinoxes and solstices by the month in which they occur —
 so the ``March Equinox``, for example, is followed by the ``June Solstice``.

skyfield/almanac.py

@@ -48,13 +48,27 @@ def fraction_illuminated(ephemeris, body, t):
     'Winter',
 ]
 
+SEASONS_SOUTH = [
+    'Autumn',
+    'Winter',
+    'Spring',
+    'Summer',
+]
+
 SEASON_EVENTS = [
     'Vernal Equinox',
     'Summer Solstice',
     'Autumnal Equinox',
     'Winter Solstice',
 ]
 
+SEASON_EVENTS_SOUTH = [
+    'Autumnal Equinox',
+    'Winter Solstice',
+    'Vernal Equinox',
+    'Summer Solstice',
+]
+
 SEASON_EVENTS_NEUTRAL = [
     'March Equinox',
     'June Solstice',