5. The horizon in the west is where sun disappears in the late afternoon. In the morning when sun appears in the east he is like an newborn baby, at noon he is standing tall, and in the afternoon he shrinks - he is growing old. His disappearance in the west was called 'the biting of the sun' (Chikin) by the Maya:

"The manik, with the tzab, or serpent's rattles as prefix, runs across Madrid tz. 22 , the figures in the pictures all holding the rattle; it runs across the hunting scenes of Madrid tz. 61, 62, and finally appears in all four clauses of tz. 175, the so-called 'baptism' tzolkin. It seems impossible, with all this, to avoid assigning the value of grasping or receiving. But in the final confirmation, we have the direct evidence of the signs for East and West. For the East we have the glyph Ahau-Kin, the Lord Sun, the Lord of Day; for the West we have Manik-Kin, exactly corresponding to the term Chikin, the biting or eating of the Sun, seizing it in the mouth." (Gates)

The pictures (from Gates) show east, north, west, and south; respectively (the lower two glyphs)  'Lord' (Ahau) and 'grasp' (Manik). Manik was the 7th day sign of the 20 and Ahau the last.

I imagine the Lord was the sun and that in Likin (east) we see him (in the top, inverted Ahau, sign) depicted in triplicate: viz. as morning, noon, and evening sun. The 20th day sign, Ahau,  therefore is showing the upside down situation, with noon sun at the very bottom.

When sun goes down at the horizon in the west it is a sign of the arrival of darkness. Saturday is the 7th and last day in the week and has connotations of earth - it is the day when sun goes down 'into the earth', I think. He is received 'by mother earth' who lies in the west waiting (as when Hine nui te Po was waiting for Maui).

In order to 'come alive again' in the morning the day after, the fire of the sun must be rekindled. I imagine these Maya pictures tell about the process, in which at bottom the 'grasping hand' returns the 'fire':

(Gates: Dresden tzolkin 15)

I do not suggest the rima glyph type means 'west' or 'grasping hand'. I do suggest rima (the normal variant chosen by me to represent the glyph type) illustrates an open and empty hand, which may have the basic meaning of 'zero'. All fingers are seen, none is remaining. The phases of the day (and similar) are over, nothing remains.