314 + 42 = 356 is close but 4 is missing. Those 4 pop up once again. We need 4 to cover the distance from 360 to 364 too. 4 could be the cardinal points. If we think of those as being born during the first 4 black nights (and the new year in the 5th), then they are 'inherently' outside of the 'regular' calendar. These 4 'poles' do not belong to the 'regular' 360 days of the solar calendar.

If they are on the outside of the year, then they must also be on the outside of the circle.

Now we have a further clue to the problem with those 648 glyphs. We should take a string 100 long (not 50) and then the circumference will be 628. Why the difference 20?

I think that if you try to write a good calendar of the year, then it is natural to think of a circle, then about π and then about the difference between (in this case) 720 and 628 = 92. We naturally consider double years, as we always think of twins in time.

A possible solution: π is a 'transcendental' number, not possible to understand rationally, not reachable by counting in any ordinary way. But this strange number may be approximated by 22/7 which give us 3.14 ... (we can disregard those innumerable figures coming after 4).

Let's add 20, then we get 42/7 = 6, a good number. We have now manipulated away 0.14 and instead we have 0.6 (i.e. we have 3.6 instead of 3.14 ...).  Of course we could as well start with 42 at once instead of doing it by adding 22 and 20, but some secrets are nice to have embedded in the rongorongo texts. (I know that 42/7 = 6 and not 0.6 but decimal points do not exist in this mythical world.)