In the G calendar the situation seems to be different (according to how we so far have interpreted the calendars of E and G), because the hônu arrive at autumn equinox (and not at midsummer):

						Ga5-4--16 (periods 17-18) tell about autumn equinox
Ga5-4	Ga5-5	Ga5-6	Ga5-7	Ga5-8	Ga5-9
Ga5-10	Ga5-11	Ga5-12	Ga5-13	Ga5-14	Ga5-15	Ga5-16
					Period 19 illustrates the 'night fall' (vero).
Ga5-17	Ga5-18	Ga5-19	Ga5-20	Ga5-21
Ga5-22	Ga5-23	Ga5-24	Ga5-25	Ga5-26	Ga5-27	Ga5-28	Ga5-29

The differences between the E and G calendars therefore need to be elucidated.