The Maya Indians had an advanced positional system for counting with 20 as its base (not 10). But when they were counting time they made one exception - instead of the expected 20 * 20 = 400 days they had 20 * 18 = 360 days. This must have been a concession to the length of the solar year, I think. Counting the path of Sun must be cut short.

But there are astronomical reasons for counting also time in cyclels of 20 * 20 = 400 days, because the synodic period of Jupiter is 399 days.

If the mystical zero once was likened to the unknown contents of an egg (0) from which a new 'bird of fire' was to rise when the new cycle began, then calendar time could follow the rhythm of Jupiter ('Father Light') and a calendar with 399 days (+ 'one more') would be the result.

Moon disappears to be rejuvenated once in a month, a night with 0 light. The theory of correspondences then finds 364 = 14 * 26 as the natural measure for the year (similar to 4 * 7 = 28 for the month). And before next cycle of 364 days can begin there must be a day with 0 light (at least in theory, but it would help to stamp out all the kitchen fires).

Therefore the synodic period of Jupiter cannot begin again until the day of 0 has passed away. There cannot be a new 'bird' without an 'egg'.

In the text of G this Jupiter 'egg' could be what is illlustrated as a fist held high in Gb6-17:

Gb6-16 (399)		Gb6-17 (0)

The picture below (which I have mirrored in order for it to better agree with tagata in Gb6-17) is from Heyerdahl and we can see the gesture of triumph - the winner of the yearly manu tara contest is holding his egg high:

In H the cycle is not of Jupiter:

side b		side a
	53	299
Hb11-50			Ha6-25 (300)
1			354

Instead of 399 side a has 299 glyphs followed by an 'egg' (Saturn is responsible for igniting the new 'fire' - the day beyond is a day of Sun).

99 is a number characterizing the Venus 'bird':

"After five complete cycles totaling 2,920 days, the movement of Venus fill eight idealized years of 365 days each and come within hours of spanning 99 lunations ..." (Popol Vuh)

With both the cycles of Jupiter and Venus exhibiting 99 the theory of correspondences will force also Sun into this pattern. Thus the cycle of Sun should be 299 + 0.