5. The whole cycle in G has 2 * 236 = 472 glyphs, 72 more than 400:

				65	115
Gb6-21	Gb6-22	Gb6-23	Gb6-24
4				180

	24		45
Ga5-5 (116)		Ga6-1 (141)		Ga7-17 (187)
72

	214
Ga7-18 (188)		Gb6-20 (403)
216

The front side can be said to measure 4 + 180 + 72 = 4 + 7 * 36 = 256 glyphs. The back side will then measure 6 * 36  = 216 glyphs, and 472 = 4 + 13 * 36. But a tzolkin has 260 days, 4 more than 256:

... the beginning of the 'sacred tonalamatl', at the Spring equinox with the Mayas as with the Mexicans, and in the center of the 364-day year (52 days of which preceded and 52 followed the tonalamatl or tzolkin), ruled by its 91-day quarters by the Four Bacabs, whose quarternary repetition (in the 1820-day period) we have thus verified ...

52 = 4 * 13	130	spring equinox	130	52 = 4 * 13
	260 = 4 * 65
364 = 4 * 91

364 is a measure for the Sun year, while the G text is longer and probably basically determined by Moon. It is created south of the equator. Instead of 364 we should therefore try with 354:

59	49	128	spring equinox (?)	128	49	59
		256 = 8 * 32
	354 = 3 * 118
472 = 4 * 118

Moon has 2 faces which will complicate the structure as compared to the simpler Sun. 49 = 7 * 7 can possibly be interpreted as a sign which means 'twice the 7 of the earth turtle'. A turtle has two half-shells and only the upper one (the 'cap') will sometimes be up in the light ('ebb'), while the 'cup' shell constantly (excepting the time of egg-laying) will be down in the sea.

Next we should make room for 236, which can be done quite easily:

59	49	128	spring equinox (?)	128	49	59
108					108
236				236
472 = 2 * 236

Instead of 4 quarters (Sun) there should be 2 halves for Moon. The ancient pattern probably stipulates ⅔ for Sun, twice as much for the male as for the female.

The central point is hardly identical with spring equinox. In the text it is easily found:

Gb1-1	Gb1-2	Gb1-3	Gb1-4
Gb1-5	Gb1-6 (236)	Gb1-7	Gb1-8
Gb1-9	Gb1-10	Gb1-11	Gb1-12

Counted from what probably is midsummer (day 177) there are 59 days to the central point:

59	49	69	59	central point	59	69	49	59
108		128			128		108
236 = 8 * 29½					236 = 8 * 29½
472 = 2 * 236