Looking through the text of G searching for reversed heads (indicating seasons with no future), I find only these six glyphs which may carry such a message:

23
	Ga6-9	Ga6-10	Ga6-11

Gb2-17	Gb2-18	Gb2-19	Gb2-20	Gb2-21	Gb2-22
Gb2-23	Gb2-24	Gb2-25	Gb2-26	Gb2-27	Gb2-28
Gb2-29	Gb2-30	Gb2-31	Gb2-32	Gb2-33	Gb2-34

Gb7-31	Gb8-1	Gb8-2	Gb8-3	Gb8-4	Gb8-5

Gb8-6	Gb8-7	Gb8-8	Gb8-9	Gb8-10
Gb8-11	Gb8-12	Gb8-13	Gb8-14	Gb8-15
Gb8-16	Gb8-17	Gb8-18	Gb8-19	Gb8-20
Gb8-21	Gb8-22	Gb8-23	Gb8-24	Gb8-25
Gb8-26	Gb8-27	Gb8-28	Gb8-29	Gb8-30

Ga6-9--10 read together probably gives a sign which depreciates (or at least changes) the value of the observation that the person in Ga6-9 is looking backwards.

Similarly, Gb2-29--30 appears to be a pair with opposed directions.

Gb8-14 and Gb8-24, on the other hand, constitute a pair which both look backwards. Their strange heads and their numbers indicate they belong together.

Having become acquainted with these pairs, Gb8-5 shines like a beacon - there is no partner glyph to pair with.

Gb1-13 is questionable - does it pair with Gb1-18 or not?

These visual impressions need to be supplemented by numbers:

Ga6-9	Gb1-13	Gb2-30
149	242 = 2 * 11 * 11	285 = 3 * 5 * 19
Gb8-5	Gb8-14	Gb8-24
446 = 2 * 223	455 = 5 * 7 * 13	465 = 5 * 93

The pair Gb8-14 and Gb8-24 obviously carries numerical signs. 455 = 5 * 91 which can be regarded as 5 quarters in a system with 4 * 91 = 364 as cycle, while 465 = 5 * 93 gives the cycle 4 * 93 = 372 (equal to a year with 31 days in each month).

Gb2-30 possibly says 15 * 19, which could be understood as the final for both moon (15) and sun (19). 285 = 9.5 * 30 = 10 * 28.5.

Gb1-13 has no obvious strong numerical signal (unless 242 is '2nd 42'), but its position immediately beyond the 9 important 'calendar regulator' glyphs is a strong sign, strengthening its visual impact.