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

• The Kollam era is attributed to the legend of the hero Para?ur?ma, an avatar (incarnation) of the god Vishnu. It is sometimes divided into cycles of 1,000 years reckoned from 1176 BCE (Before Current Era). Thus, 825 CE (Current Era) would have been the first year of the era’s third millennium. Para?ur?ma, was however, a contemporary of R?ma, whose birth date is estimated to be in 5114 BCE (if not earlier). It is, therefore, unclear if the Para?ur?ma associated with the Kollam era is the same as the Para?ur?ma of R?m?yana.
• The news of the physical disappearance of Sri Adi Shankaracharya in 820 CE at Kedarnath reached Kerala only a few years later. It is believed that Kerala began the Malayalam era, also called the Kollam era, in 825 CE in his memory. There is, however, a differeing opinion that Sri Adi Shankaracharya was born in 509 BCE and died in 477 BCE.
• The origin of Kollam Era has been dated to 825 CE, when the great convention in Kollam was held at the behest of King Kulashekhara. Kollam was an important town in that period, and the Malayalam Era is called 'Kollavarsham', possibly as a result of the Tharisapalli plates.
• According to Hermann Gundert, Kollavarsham started as part of erecting a new Shiva Temple in Kollam and because of the strictly local and religious background, the other regions did not follow this system at first. Once Kollam port emerged as an important trade center, however, the other countries also started to follow the new system of calendar. This theory backs the remarks of Ibn Battuta as well.^[10][11]
• It is believed that the era was started by the East Syrian saints Mar Sabor and Mar Proth who settled in Korukeni, Kollam, near to the present Kollam.^[10][12][13]

The Malayalam months follows the Sanskritic Sauram?sa (solar month) naming convention. Thus, Cingam is named after the corresponding Sanskrit solar month, the Simham, and so on. This is unlike the case in Tulu 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 (????), meaning week.

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

Vishu (????), celebrated on the 1st of Metam, and Onam (???), celebrated on the star Thiruvonam [t?iru?o???m] in the month of Chingam, are two of the major festivals in Kerala. In Indian astrology, the passing of the sun into Aries at the vernal equinox on Metam 1, now calculated to fall on April 14, is generally celebrated as Vishu (derived from the Sanskrit Maha Vishuva Sankranti, the word "sanGkrAnti" ??????????? meaning "transference or transition to"), and was considered a candidate for marking the start of a year.^[14] However, a conference of astronomers that the king Udaya Marthanda Varma summoned in 825 CE, resolved to start the New Year on the first of Chingam (in mid-August). While Cochin, Madurai, Tirunelveli and Ceylon followed suit,^[15] Palghat and North Kerala retained another ancient mode of reckoning the New Year from the first day of Kanni (Virgo) in September.

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 Karka?akam 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.)

Chaitram 1 (usually coinciding with March 20) or Metam 1 (usually coinciding with April 14), both in the proximity of the date of the vernal equinox (March 21), mark the beginning of the new year in many traditional Indian calendars such as the Indian National calendar and the Tamil calendar. When the Government of Kerala adopted Kolla Varsham as the regional calendar, the 1st of Chingam, the month of the festival of Onam, was accepted as the Malayalam New Year instead.

Many events in Kerala are related to the dates in the Malayalam calendar.

The agricultural activities of Kerala are centred on the seasons. The southwest monsoon which starts around 1 June is known as Etavappathi, meaning mid-Etavam. The northeast monsoon which starts during mid October is called thulavarsham (rain in the month of thulam). The two harvests of paddy are called Kannikkoythu and Makarakkoythu (harvests in the months kanni and makaram) respectively.

• Bengali calendar
• Hindu calendar
• Kanippayyur Shankaran Namboodiripad
• Tamil calendar