 At the equinoxes of March and September, the Sun rises in the valley right between the two hills.Chía and Sué formed the basis of the complex Muisca calendar, where synodic and sidereal months were taken into account in three types of years; rural years of 12 or 13 months, common years of 20 months and holy years of 37 months.Weeks with weekly markets were 4 days, making every month 7 weeks.