Ideas:

1. In the calendar for the month in Mamari it is certain that this type of glyph (concave towards the right) stands for a night. Here in Keiti we may therefore expect some similar meaning. There are, however, no more than 10 such glyphs (13 if we count also the mixed glyphs). And I believe that my 9 'periods' in Keiti do cover a whole month, not part of a month.

2. The number of nights in the month of Keiti is - I suspect - shown in another way. In order to find the method I have made a little table for the middle part of each 'period'.

From this table it is clear that there are twins of this type of glyph only in 'periods' nos. 3 and 6. In 'period' no. 8 there are twins of the moon turned the other way around (mirrored). In 'period' no. 7 there are two moon-like glyphs too, but one turned to the left and other to the right. In the 'periods' nos. 1, 2, 4 and 5 there are 'persons' involved in some way.

Comparing with the calendar in Mamari I draw the conclusion that probably the two 'periods' 3 and 6 in Keiti correspond to the periods 2 and 5 in Mamari. From now on I consequently will call also the 'periods' in Keiti for periods.

3. In period no. 3 we must try to find six kokore-nights and in period no. 6 five such nights. I think I have found them. I believe that the glyphs looking like 'staffs' are involved.