I would respectfully disagree with this. The Mayan solar year was the most accurate known to man until the 20th century, when the length of the solar cycle was determined to be somewhat less than 365.25 days. The Mayan Venus cycles are precise, as are the eclipse tables. The knowledge was not lost, just hidden for centuries, preserved by men and women of knowledge, and it is slowly resurfacing and being taught in small towns to the new generations. Their civilization is not really failed, they just took a break to survive the invasion of their land and the supression of their culture. The Mayan cosmology is not as divorced from the scientific as you might think, it is just shrouded in the imagery of Mayan linguistics and philosophy.

The solar year in the Yucatan begins on the day of the second transit of the sun on the local zenith. Conveniently, the equinoxes, both solar nadir transits and both solar zenith transits occur on the first day of a Mayan "month".

Their knowledge is not superior to the science of our age, but it is not far behind. Honestly, the Mayan calendar is only relevant at latitudes between 15 and 21 north latitude, as it predicts the 5 local seasons with accuracy, in a way that the Gregorian calendar does not, since it was developed at latitudes outside the tropics, where there are 4 seasons.