There are two types of ancient vedic calendar systems:
1. Lunar (moon) calendar
2. Solar (sun) calendar
Most scholars who have analyzed these old vedic calendar systems, have concluded that the lunar system is the more ancient. The lunar phases are known to influence agriculture, and according to scriptures like Manu-samhita (The Law of Manu) they also influence more subtle aspects of human life.
Gaurabda is the name of lunar calendar based on Lord Sri Caitanya Mahaprabhu's appearance year. Lord Sri Caitanya Mahaprabhu is Krishna's incarnation in Kali-yuga. He appeared in 1486 at Sridhama Mayapura in the city of Navadvipa, West Bengal, India. Lord Caitanya was also known as Gaura because of His beautiful golden complexion. So the calendar based on this Golden Incarnation of Krishna is called Gaurabda. It is used as the main calendar of the International Society for Krishna Consciousness & Gaudiya vaishnava followers.
The years in Gaurabda calendar are counted from the appearance day of Lord Sri Caitanya Mahaprabhu. In Gaurabda vaisnava calendar the times for various celebrations are determined by the tithi, sometimes with naksatra and other elements of the calendar taken into account. Each month, or "masa," is known by a name of Visnu.
Following is the rough equivalents of Gaurabda masa (months) to their common Sanskrit names, Gregorian calendar, Solar month, Sun signs and Season:
| Gaurabda Masa | Sanskrit / Hindu Month | Gregorian / English Month |
Rashi / Solar Month
|
Zodiac Sun Sign |
Ritu / Season
|
|
| 01 | Vishnu | Caitra | March–April | Mesh | Aries | Vasant |
| 02 | Madhusudana | Vaisakha | April–May | Vrushabh | Taurus | (spring) |
| 03 | Trivikrama | Jyestha | May–June | Mithun | Gemini | Grishma |
| 04 | Vamana | Asadha | June–July | Kark | Cancer | (summer) |
| 05 | Sridhara | Sravana | July–August | Simha or Sinh | Leo | Varsha |
| 06 | Hrsikesa | Bhadrapada | August–September | Kanya | Virgo | (monsoon) |
| 07 | Padmanabha | Asvina | September–October | Tula | Libra | Sharad |
| 08 | Damodara | Kartika | October–November | Vrushchik | Scorpius | (autumn) |
| 09 | Kesava | Margasirsa | November–December | Dhanu | Sagittarius | Hemant |
| 10 | Narayana | Pausa | December–January | Makar | Capricornus | (autumn-winter) |
| 11 | Madhava | Magha | January–February | Kumbha | Aquarius | Shishir |
| 12 | Govinda | Phalguna | February–March | Meen | Pisces | (Winter-Spring) |
| Extra | Purusottama | Adhika | Intercalary Month | |||
