Kin (days)

The Maya year had a basic unit called Kin, a word that means day or sun. The Tzolkin calendar had a cycle of 20 day names combined with a cycle of 13 day numbers. Each of these 20 names had a glyph to represent it. To measure passages of time, priests studied the sun, the moon, and Venus. 

The calendar had 18 months with 20 days, then a month with 5 unlucky days. The Maya also had a religious calendar which had 260 days in it.  Each day was given a name and a number:

image from mayankids.com

 

Uinal (months)

A Maya year had 19 months called Uinal. Each had a name and a corresponding glyph.

The first eighteen months had twenty days each. The last month, called Uayeb, had only five days. The days within a month were numbered from 0 to 19 (not 1 to 20) with the exception of Uayeb’s days which were numbered 0-4.

image from mayankids.com

 

(Adapted from source)