Why are there doosra months in some years?

By Arabinda Ghose

There are twelve months in a ?Hindu? calendar. They are: Chaitra, Vaishakh, Jyestha, Ashadha, Shravan, Bhadra, Ashwin, Kartik, Agrahayan (or Marga-shirsha), Paush, Magh and Phalgun. A ?Hindu? calendar may be both lunar or solar.

However, most of us living in and around Delhi and the neighbourhood are familiar with the lunar calendar only in which there are twelve months as described above. In several states of India, the lunar calendar is not in vogue. It is the solar calendar that is followed, but with no changes in the names of the months or their sequence, in several eastern states, as also in the kingdom of Nepal.

A lunar month begins from the first tithi (not day) after either the Amavasya (new moon) or the Poornima (full moon). As we will see later, these lunar months create all the ?trouble? about pehla and doosra lunar months-whether Shravan or Paush or Phalgun.

A solar month, on the other hand begins from the day the sun ?enters? a particular rashi (sign of the Zodiac). As most of us are aware, there are twelve rashis in a year-Mesha (Aries), Vrishabha (Taurus), Mithun (Gemini), Karkat (Cancer), Simha (Leo), Kanya (Virgo), Tula (Libra), Vrishchika (Scorpio), Chanu (Sagitarius), Makar (Capricorn), Kumbha (Aquarius) and Meen (Pisces). The day the sun remains in the twilight zone between two rashis is called the sankranti. There are actually twelve sankrantis in a solar year but we are familiar with just two-the Makar Sankranti, the day the sun begins its ?journey? towards the north after ?reaching? the Tropic of Capricorn and the Mahavishuva Sankranti, the day the sun is ?on? the equator, and day and night are of the same duration, i.e. 12 hours that day, all over the world.

For traditionalists, the new solar year begins on the first day of Vaishakh, which is known as the Pehla Baishakh in Bengal, Baisakhi in Punjab, Rongali Bihu in Assam and Vishu in Kerala. The corresponding date in the Gregorian (English or the Christian) calendar is April 14 or 15. In Nepal and some other areas, the corresponding date is April 13. The difference occurs because while in Nepal and some areas, the new months begin on the Sankranti day, in other regions such as Bengal, it begins after the Sankranti day.

Scientifically speaking, however, the solar year begins on the Vernal Equinox day which falls generally on March 21 every year according to the Gregorian calendar.

The solar year begins on the Vernal Equinox day which falls generally on March 21 every year according to the Gregorian calendar.

One must make it clear that the ?movements? of the sun across the heavens and the paths it traces among the stars-the ?fixed? stars-are all apparent. Because the earth rotates around its axis once in 24 hours and while revolving around the sun, we earthlings ?feel? as if the sun rises in the east and sets in the west as it moves from one rashi to another and sometimes ?engineers? the doosra months and the like.

Now about the moon. This is the only satellite the earth has. Although it takes 27 days for the moon to cover these 27 nakshatras, the earth moves ahead during these 27 days, so that in order to reach the original point of start of the moon, it takes two more days of journey. Thus a lunar month is of twenty-nine-and-a-half days´ duration. Roughly, therefore, a lunar year consists of twenty-nine-and-a-half x 12, or about 354 days. A solar year, on the other hand, consists of 365 days. This anomaly creates a lot of problems.

Actually, a solar year consists of 365.24219 days while the duration of a lunar year is 354.3672 days. The difference is of about 11 days. So, if we suppose that both the solar and lunar years begin on the same day, the lunar year will end within about 354 days. If this goes on, then very soon the lunar year would go on lagging behind the solar year by about 11 days a year, or about 33 days in three years. What is wrong in that, one may well ask?

Well, the seasons occur according to the movement of the sun, and not the moon. Chaitra Shukla Pratipada (the Varsha Pratipada, the Yugadi, the Gudi Padwa, the Cheti Chand), the first day of a lunar year begins normally during the spring season. However, if we follow the lunar calendar, then this tithi (not day) will fall 33 days earlier after three years, when it will be winter. Another three years later, with a lag of 66 days, the Varsha Pratipada will occur during the autumn.

This is precisely what happens in the case of the Islamic calander and hence you will find that the festivals or religious events occur all the year round with respect to the Gregorian calendar. Thus, you can celebrate Eid in different seasons in different years.

The Hindus devised a unique system which ensured that there was no incompatibility between months and seasons according to the lunar calendar with respect to the solar calendar. So every three years, by which time the lunar months lag by more than one month, one particular lunar month is ?repeated?. Thus we have in this lunar year, two Shravans so that the year catches up with the solar calendar. This extra month is called the adhik or mala mas (intercalary month) and no religious functions are held during this month. That is why this year the Ganesh Chaturthi fell on September 18 and the Ananta Chaturdashi, the day the idols are immersed, on September 28.

There are seven intercalary months falling in a cycle of 19 years. So, the intercalary month is added every 2.7 years (19 divided by 7). However, one cannot designate just any lunar month as an intercalary month according to Hindu astronomy. If there are two Amavasyas within one solar month, that lunar month in the same name (Amavasya to Amavasya) is termed the adhik or mala month. This year, lunar Shravan month qualified for this (dis)honour. Hence the doosra Shravan.

There should normally be no relationship between the extra lunar months and rainfall, since the moon does not have any role in creating seasons. It is the prerogative of the sun only. However, ancient Indian astrologers had established some relationship between lunar movements and weather, particularly, rainfall. However, that is another matter and can be discussed in another article.