cided with the years in which the lunation fractions of Z11 and Z12 were greater than <span class="nowrap">12/19</span>. After <span class="nowrap">N<sub>-162</sub></span>, only the dates of Z12 and Z1 were fixed to a month and the leap years only coincided with the years in which the lunation fractions of Z1 were greater than <span class="nowrap">12/19</span>. This information may provide an important clue to the intercalation rules used by the calendar systems from <span class="nowrap">N<sub>-245</sub></s