Edavam

Malayalam calendar or Kollam Era, also known as Kollavarsham, is a solar and sidereal Hindu calendar used in Kerala, India. The origin of the calendar has been dated as 825 AD (Pothu Varsham) at Kollam.

There are multiple conflicting accounts regarding the origins of the Malayalam calendar, some of which are mentioned below:

The Malayalam months follows the Sanskritic Sauramāsa (solar month) convention. Thus Cingam is named after the corresponding Sanskrit solar month, the Simham, and so on. This is unlike the case in Tulu and Tamil calendar which follow the names of lunar months. The following are the months of the astronomical Malayalam calendar:

The days of the week in the Malayalam calendar are suffixed with Aazhcha (ആഴ്ച), meaning week.

Like the months above, there are twenty seven stars starting from Aswati (Ashvinī in Sanskrit) and ending in Revatī. The 365 days of the year are divided into groups of fourteen days called Ñattuvela (ഞാറ്റുവേല), each one bearing the name of a star.

Vishu (വിഷു), celebrated on the 1st of Metam, and Onam (ഓണം), celebrated on the star Thiruvonam [t̪iruʋoːɳəm] in the month of Chingam, are two of the major festivals. The first day of Chingam is celebrated as the Kerala New Year replacing Vishu (വിഷു), which was till then considered the beginning of a year.

The Makaravilakku festival is celebrated in the Ayyappa Temple at Sabarimala on the 1st day of month Makaram. This marks the grand finale of the two-month period to the Sabarimala pilgrimage. The 1st of Makaram marks the Winter Solstice (Uttarayanam) and the 1st of Karkaṭakam marks the summer solstice (Dakshinayanam) according to the Malayalam calendar. (According to the astronomical calendar the summer solstice is on June 21, and the winter solstice on December 21)

...
Wikipedia