This glyph is the last in what I call the '1st period'. The '2nd period' has no special glyphs beyond the first five, only six moon-symbols, which I interpret as six tapu-free nights. Six nights without tapu in the '2nd period' implies that I believe that the '1st period' suffers from tapu.
Barthel has written about the names of the nights in the lunar month and I think that at least some of the tapu-free nights are called kokore followed by a number. This word I believe means ko-kore = 'the one without', i.e. without tapu.
There are 6 kokore before Full Moon (= '2nd period') and 5 after (= '5th period'), given that my interpretation is right.
1. This type of glyph seems to show some type of head gear. We can see the top of a head with ears and from the ears there are hanging 3 + 4 = 7 feathers or something similar.
2. Is this number indicating the number of the days in the week?