We can recognize this type of glyph from the last glyph (Eb6-19) in the last period (24th) of the Keiti calendar of the year:

Does this glyph (Hb5-9) mean that something is ending? From the parallel Pb7-1 it seems that there is a close association with the preceding glyph, which then possibly may indicate what is ending:

H
P

I cannot see any similarity between the glyphs preceding Eb6-19 and those surrounding Hb5-9.