What was similar about the Mayan and Aztec calendars
Both the Mayan and Aztec calendars were based on a complex system of timekeeping and utilized a combination of solar and ritual cycles. Both calendars were highly accurate and sophisticated for their time. They both incorporated a year of 365 days divided into 18 months of 20 days each, with an additional 5 or 6 "unlucky" days at the end to balance out the solar year.
Additionally, both calendars had a similar focus on cycles and the interplay between celestial and earthly events. They assigned specific meanings and rituals to different time periods and utilized astronomical observations for the purpose of religious and agricultural practices. Both calendars also contained long counts, which measured time in cycles of several thousand years.
It is worth noting that while the two calendars share similarities, they are not identical, and had some differences in terms of specific rituals, glyphs, and interpretations.