The triple formation of the glyphs in period 10 possibly suggests that the time from new year to summer solstice is divided in three parts:

10
	Eb3-32	Eb3-33	Eb3-34
	Eb3-35	Eb3-36	Eb3-37
	Eb3-38	Eb4-1

180 days / 3 = 60 days in each part.