Tamil Calendar is a sidereal solar calendar, which means the calendar is based on the motion of the Earth around the Sun with respect to the fixed star. It is based on the classical Indian Hindu Calendar.
Tamil calendar is followed in the Indian states of Tamilnadu and Puducherry. And by Tamilians in Sri Lanka, Malaysia, Singapore, Mauritius, etc.
Same as in other western or Hindu calendars, there are 12 months in the Tamil calendar as well.
The number of days in a Tamil calendar month varies from 29 days to 33 days.
List of 60 Tamil Year Names.
April 14th marks the start of the Tamil new year and is celebrated as Puthandu, also called Puthuvarudam.
Below is the list of Tamil months, related zodiac stars, and equivalent Gregorian months.
| Tamil Month | Gregorian Calendar Equivalent | Related Zodiac Star in Tamil |
| சித்திரை (Chiththirai) | mid-April to mid-May | மேழம் (Merham/Mezham) |
| வைகாசி (Vaigaasi) | mid-May to mid-June | விடை (Vidai) |
| ஆனி (Aani) | mid-June to mid-July | ஆடவை (Aadavai) |
| ஆடி (Aadi) | mid-July to mid-August | கடகம் (Kadagam) |
| ஆவணி (Aavani) | mid-August to mid-September | மடங்கல் (Madangal) |
| புரட்டாசி (Purattaasi) | mid-September to mid-October | கன்னி (Kanni) |
| ஐப்பசி (Aippasi) | mid-October to mid-November | துலை (Thulai) |
| கார்த்திகை (Karthigai) | mid-November to mid-December | நளி (Nali) |
| மார்கழி (Margarhi/Margazhi) | mid-December to mid-January | சிலை (Chilai) |
| தை (Thai) | mid-January to mid-February | சுறவம் (Churavam) |
| மாசி (Maasi) | mid-February to mid-March | கும்பம் (Kumbam) |
| பங்குனி (Panguni) | mid-March to mid-April | மீனம் (Meenam) |