That is to say, the important 3900 multiplied by the days of the lunar year
and also by those of the solar year, hence the 719, referred to under 4,
separates into these two parts. The lunar year of 354 = 6 × 29 + 6 × 30
days was not unknown to the Mayas. We shall find its half, 177 days,
several times on pages 51-58.
We might also use the two important numbers 14,040 and 18,980, the first of
which is divisible by 260 and 360, and the second by 260 and 365, without
remainder.