Ohoga means departure. Kohata is Mangarevan for 'the space between two boards, to be badly joined'.
Aa2-1	Aa2-2	The haga rave glyph type could depict the course of the sun, first moving down towards Easter Island, then making a turn at the bottom, followed by a crack and then autumn. Badly joined it is, but there is only a single 'board' (spring), with 'winter' comes 'water' (vai).
Ko te ohoga	i vai ohata

The change of year seems first to be described by the end of the previous year (tagata) and then by the shape of the new year. Possibly there is also a hint in form of the 'fist' at top right in Aa2-1 - it seems to be on its way to come loose, to be the 'nut' from which the new year will grow. In Aa2-2 we can at right read a sign of autumn. The summary at tagata illustrates this type of sign at right in Eb5-4, where 5 * 4 = 20(0):

Eb5-4

summer (from spring to autumn equinox)

I therefore guess Aa2-1 refers to winter solstice and Aa2-2 to summer solstice.