Maybe 26 in the last period of the E calendar tells about how during a year there are 26 fortnights (14 * 26 = 364). With 20 in the first period possibly representing 20 * 18 (= 360) solar days, 26 may mean 364 lunar nights.

Counting would proceed upwards with waxing sun to the 10th period. Beyond that comes the time of the moon and sun wanes.

Vero in the 11th period means sun rules no more. Vero in the 19th period has a sign of the moon:

It may mean that moon has no more time to rule. With the 20th period darkness arrives. Moon will thereby have an equal amount of glyphs as the sun: