The Moon age was counted by the Maya as given on various inscriptions (using glyph D and/or E). Ethnohistorical sources and the analysis of the Eclipse Table working for Solar eclipses at New Moon leads to assumption, that the Moon age count started at New Moon or one day later at the first visibility of the Moon. Therefore New Moon should fall at 126.96.36.199.8 12 Lamat 1 Muwan.
This mean, the Moon age is 26 days since the arrival of the Moon (New Light), it is seen the 4th month of skull Moon, and the month is 30 days long. Glyph X is the name of Moon with unknown meaning.
The Moon age is the most well understood astronomical phenomena of Maya astronomy. It establishes the most stringent test of any correlation of the Maya calendar.