Ideas:

1. This glyph is located close to a night which in a Hawaiian Moon calendar did not have any name. Maybe this unnamed night corresponds to the night which on Easter Island was called Orongo and which, I guess, is connected to this glyph at the end of the '6th period'.

2. The reason for this night being unnamed perhaps had to do with unease, a night to be feared. If so, then I guess that is because this night could be the 'odd' night which only appears once in the double-moon period of 59 nights.

3. I suspect that the addition of a thread with 5 hanging objects (feathers?) to the ordinary night-glyph, is used as a sign for showing that a period is finished. This thread with objects is hanging on the left side (instead of the usual right side) and that therefore is yet another sign, a sign - I think - which points to something just passed.