Open the almanac that sits beside the puja shelf in many Hindu homes and you find a page crowded with Sanskrit names and timings given to the minute. This is the panchang (in the south, panchangam), and for most of Indian history it was the only calendar anyone needed. It told the farmer when to sow, the priest when to begin a rite, the family when to hold a wedding, and the village when the next festival fell.
To a newcomer it looks impenetrable. It is not. A panchang is built from a handful of ideas, and once you hold them the page opens up. This article walks through those ideas and ends by reading one day's entry together.
A calendar that follows both Moon and Sun
The Hindu calendar is lunisolar. Its months are lunar, each running from new moon to new moon, about twenty-nine and a half days. Its year is solar, anchored to the Sun's path so that the seasons stay in place: Holi is always in spring, Diwali always in autumn. Twelve lunar months fall about eleven days short of a solar year, so a correction is needed every few years. We will come to that.
Each lunar month is divided into two halves called pakshas, "wings". Shukla Paksha, the bright half, runs from new moon to full moon as the Moon waxes; Krishna Paksha, the dark half, runs from full moon back to new moon as it wanes. Observances are named by paksha and day: Janmashtami is Krishna Ashtami, the eighth of the dark half; Rama Navami is Shukla Navami, the ninth of the bright half.
Why the north and south name the month differently
This puzzles families with roots in different regions. In the south, Gujarat and Maharashtra the month begins at the new moon; this is the amanta system, from amavasya, new moon. In most of north India the month begins the day after the full moon; this is purnimanta, from purnima. The two systems agree on every bright half but attach each dark half to different months. So Krishna's birthday falls in Shravana for a Gujarati family and in Bhadrapada for a family from Uttar Pradesh, and the new moon of Diwali closes Ashvina in the south and Kartika in the north. It is the same night under two labels, and the lamps are lit everywhere at once.
The five limbs
Panchang means "five limbs" (pancha, five; anga, limb). Each day is described by five quantities.
Tithi, the lunar day, is the most important. A tithi is the time the Moon takes to move twelve degrees ahead of the Sun, and because the Moon's speed varies, it can last anywhere from about nineteen to twenty-six hours. Fifteen tithis make a paksha, numbered in Sanskrit: Pratipada (first), Dwitiya, Tritiya, Chaturthi, Panchami, Shashthi, Saptami, Ashtami, Navami, Dashami, Ekadashi, Dwadashi, Trayodashi, Chaturdashi, and then Purnima or Amavasya. Festivals and fasts are fixed by tithi: Ganesha's day is a Chaturthi, the fortnightly Ekadashi fast is the eleventh, Shivaratri is the fourteenth of the dark half.
Vara is the weekday, the one limb everybody already knows: Ravivara (Sunday, the Sun), Somavara (Monday, the Moon), Mangalavara (Tuesday, Mars), Budhavara (Wednesday, Mercury), Guruvara (Thursday, Jupiter), Shukravara (Friday, Venus) and Shanivara (Saturday, Saturn). Weekly vrats follow the vara: Monday for Shiva, Tuesday for Hanuman, Saturday for Shani.
Nakshatra is the lunar mansion, the one of twenty-seven star groups the Moon is passing through. It is used to choose dates, name children and match horoscopes, and deserves an article of its own.
Yoga here has nothing to do with postures. It is a calculated value, the sum of the Sun's and Moon's longitudes, divided into twenty-seven parts with names such as Siddhi, Shubha, Dhriti and Vyatipata. A few are considered unfavourable for beginnings and a priest will steer around them; most households simply note the name.
Karana is half a tithi. Eleven exist, seven of which rotate through the month. The one to watch is Vishti, better known as Bhadra. Tradition avoids starting anything important while Bhadra runs, which is why a family may wait for "Bhadra to pass" before tying rakhi on Raksha Bandhan.
The day begins at sunrise
In Hindu reckoning the day runs from sunrise to sunrise, not from midnight. The tithi in force at sunrise is, for most purposes, the tithi of the whole day. This is why a fast sometimes falls on a different date from the one a moon-phase app suggests: the app is watching the Moon, the panchang is watching sunrise. Night observances such as Shivaratri and Janmashtami follow their own rule, usually that the tithi must cover midnight.
Because of this, a panchang is always computed for a particular place. Sunrise in Chennai is not sunrise in Delhi, let alone in London or Melbourne, and the moment a tithi ends is a single instant that lands at different local hours around the world. A tithi that ends just after sunrise in India may have ended before sunrise in the Americas, moving a fast by a day. Families abroad do well to use a panchang made for their own city, and to accept that relatives in India may keep the same festival on a different date.
Leap months and solar markers
Now the correction. Roughly every thirty-two or thirty-three months, the calendar adds a thirteenth month. The rule is neat: the Sun enters a new zodiac sign about once a month, and any lunar month in which it enters none is declared adhik maas, the "additional month". It takes the name of the month that follows, with Adhik in front, and is also called Purushottam Maas, the month of Vishnu. No weddings, housewarmings or festivals are fixed in it; it is kept for reading, japa and charity. The reverse, a dropped or kshaya month, occurs very rarely.
The Sun's entry into each sign is itself an event, a sankranti, and the panchang records all twelve. Makar Sankranti in mid-January, when the Sun enters Capricorn, is kept across the country as Pongal, Lohri, Uttarayan and Magh Bihu. In Tamil Nadu, Kerala, Bengal, Odisha, Assam and Punjab the civil year is solar and begins at Mesha Sankranti in mid-April; Puthandu, Vishu, Poila Boishakh and Vaisakhi are the same new year under different names. The lunar new year of the north and west, Ugadi and Gudi Padwa, falls a few weeks earlier at Chaitra Shukla Pratipada.
Muhurta: choosing the moment
A muhurta is formally a span of forty-eight minutes, thirty of which make a day and night. In practice the word means an auspicious window, and finding one is the panchang's most used function: for a wedding, a thread ceremony, a housewarming, the opening of a shop. The astrologer weighs all five limbs together, avoiding Amavasya and certain tithis for new beginnings, preferring certain nakshatras, steering past a hostile yoga and past Bhadra, and then fixes the hour.
Two windows are known to almost everyone. Rahu kaal is a daily period of roughly ninety minutes, falling at a different time on each weekday, during which new ventures are not begun; it is observed most strictly in the south. Abhijit muhurta is the window of about forty-eight minutes centred on local noon, treated as good for nearly anything and the dependable fallback when nothing better can be found (though many astrologers set it aside on Wednesdays).
Reading one line
Here is an entry of the kind a printed almanac gives for a Tuesday in mid-October, computed for a city in India.
Ashvina, Shukla Paksha. Dashami till 13:25, then Ekadashi. Nakshatra Shravana till 09:40, then Dhanishtha. Yoga Dhriti. Karana Taitila, then Garaja. Sunrise 06:18, sunset 17:52. Rahu kaal 14:58 to 16:25.
Now read it. The month is Ashvina and the Moon is waxing. At sunrise the tithi is Dashami, the tenth, so this is Vijayadashami, the day of Dussehra, whatever a lunar app may say about the exact phase. Dashami ends at 13:25 and Ekadashi begins, but because Ekadashi is not in force at sunrise, the Ekadashi fast is tomorrow. The Moon was in Shravana at dawn, which tradition considers especially fitting for Vijayadashami, and crossed into Dhanishtha mid-morning. Dhriti is a favourable yoga; Taitila and Garaja are ordinary karanas, and Bhadra is nowhere in sight. Rahu kaal sits in the late afternoon, as it always does on a Tuesday, so anyone starting something new would choose the morning or the Abhijit window a little after noon. Every timing hangs on the sunrise and sunset, which is why the same day's line for a city abroad would read differently.
To reflect on
You do not need to master every limb to make the panchang part of your life. Learn to find the tithi, so that you know why Ekadashi or Chaturthi is being kept. Note the paksha, and check it against the Moon in the evening sky; the calendar becomes real once you have seen a Shukla Ashtami half-moon for yourself. And use a panchang computed for the place where you live. The sages built this calendar to tie human life to the sky overhead, and that sky is wherever you are standing.