Another reversed hau tea is located at the beginning of the preceding glyph line, and it is drawn exactly as in Gb5-1:

Here 320 = 10 * 32, where 32 probably alludes to the 5th term in the 'growth series': 2, 4, 8, 16, 32 ... If so, then it probably means that at Gb3-30 the season of growth is ending, which also a pau sign at bottom right indicates.

A new (black) season without growth (which needs sun light) evidently begins with Gb4-1. If we add the glyphs from Gb4-1 up to and including Ga4-2 we reach 236 = 8 * 29.5:

A takaure season (winter) with sun 'absent', a dark season, is beginning with Gb4-1 and ending with Ga4-2.

The calendar is 16 * 29.5 = 472 glyphs long (1 more than the number of glyphs on the tablet) and half the calendar describes when sun is 'absent', half when sun is 'present'.

The end of growth (Gb3-30) comes before the reversal of light at Hatinga Te Kohe (Gb5-1) and in between is Akahanga located, where the king is buried. The reversal of light does not indicate the death of the king but the succession of his rule by the queen, the moon. The events are connected, though, and the chain of events extends both backwards and forwards.

Here I find it necessary to suggest a better solution, viz. based on counting Gb8-30 twice:

The great tagata with a short neck at Ga4-1 clearly must stand at a cardinal point.

Takaure in the following Ga4-2 has 3 'feather marks' at bottom left, and we can guess it refers to the 3 months of the 'Sea' (Capricorn, Aquarius, and Pisces).

The last part of my earlier text could be wrong. Hatinga Te Kohe ought to come later than Gb5-1 if this glyph is associated with Hanga Te Pau. But a definite judgment must wait until we securely can put the kuhane stations in parallel with the G text (more secure than my attempt in the glyph type dictionary).