Amrutkaal The Six Ritus: Seasons of the Hindu Calendar
The Hindu calendar divides the year into six seasons, or ritus (ऋतु), rather than the four familiar from temperate climates. This six-fold scheme reflects the rhythm of the Indian subcontinent, where the monsoon and the gradual cooling toward winter each deserve a season of their own. The six ritus are Vasanta (वसन्त, spring), Grishma (ग्रीष्म, summer), Varsha (वर्षा, monsoon), Sharad (शरद, autumn), Hemanta (हेमन्त, pre-winter), and Shishira (शिशिर, winter). Each ritu spans two lunar months, so the six seasons together make up the twelve months of the year, and each is paired with the lunar months traditionally assigned to it. Because the lunar calendar drifts against the Gregorian one and is periodically corrected by an intercalary month, the Gregorian dates given for each ritu are approximate — they mark the broad span rather than fixed boundaries. The classification is ancient and widely cited in Sanskrit literature, where poets organised descriptions of nature, festivals, and agricultural life around this cycle of six.
The Six Seasons and Their Months
Vasanta (spring) covers the lunar months Chaitra and Vaishakha, roughly mid-March to mid-May. Grishma (summer) covers Jyeshtha and Ashadha, roughly mid-May to mid-July, the hottest stretch before the rains.
Varsha (monsoon) covers Shravana and Bhadrapada, roughly mid-July to mid-September, when the rains dominate much of the subcontinent. Sharad (autumn) covers Ashwina and Kartika, roughly mid-September to mid-November, a clear post-monsoon season rich in festivals.
Hemanta (pre-winter) covers Margashirsha and Pausha, roughly mid-November to mid-January, the early cold season. Shishira (winter) covers Magha and Phalguna, roughly mid-January to mid-March, the coldest and last ritu before spring returns and the cycle begins again.
Why the Dates Are Approximate
Each ritu is traditionally tied to two lunar months, but the lunar year of about 354 days is shorter than the solar year. To keep the months aligned with the seasons, an extra month (Adhika Masa) is inserted roughly every two to three years. This periodic correction means a given ritu does not begin on a fixed Gregorian date but shifts within a window of a few weeks from year to year.
For this reason the Gregorian spans above should be read as typical ranges, not exact start and end points. The precise season for any given date depends on the panchang for that year and, where solar reckoning is used, on the Sun's position relative to the seasonal markers. Consulting a dated panchang for your location is the reliable way to know which ritu applies on a particular day.
Frequently Asked Questions
Why does the Hindu calendar have six seasons instead of four?
The six-ritu scheme reflects the climate of the Indian subcontinent, where the monsoon (Varsha) and the transitional pre-winter (Hemanta) are distinct enough to count as seasons in their own right, giving six rather than four.
How many lunar months does each ritu span?
Exactly two. The six ritus paired with two months each account for all twelve lunar months of the year — for example, Vasanta spans Chaitra and Vaishakha.
Why are the Gregorian dates for each ritu only approximate?
The lunar year is shorter than the solar year and is corrected by an intercalary month every few years. This drift means each ritu shifts within a window of a few weeks rather than starting on a fixed Gregorian date.