Half a lunar day
A Karana is half of a Tithi, which means the time the Moon takes to gain 6 degrees on the Sun. It is the fifth and last limb of the Hindu Panchang, after the Tithi, the weekday, the Nakshatra and the Yoga. Because a lunar month has 30 Tithis, it has 60 Karanas. Each lasts roughly 9 to 13 hours, and two make up each Tithi. For the whole system, see What is Panchang?.
The word Karana means action or doing. In traditional timing it is read as the quality of work that suits a period, and so it is used mostly when picking an hour to start something.
The 11 Karanas
There are 11 names, but 60 half Tithis, so the names are arranged in two groups.
Seven movable Karanas. Bava, Balava, Kaulava, Taitila, Gara, Vanija and Vishti. They repeat in this order and cycle eight times in a month, which makes 56 half Tithis.
Four fixed Karanas. Shakuni, Chatushpada, Naga and Kimstughna. They appear only once each month, at fixed points near the new Moon, and fill the last four places.
The count of 56 plus 4 gives 60.
How the pattern runs
The cycle starts at the new Moon. The first half of the first Tithi of the bright half, Shukla Pratipada, is always Kimstughna, a fixed Karana. After that, the seven movable Karanas begin with Bava and follow in order, each one half a Tithi long. They keep repeating through the whole month. Near the end of the dark half the movable cycle stops and the fixed ones follow. The second half of the fourteenth Tithi of the dark half is Shakuni, the first half of Amavasya is Chatushpada, and the second half of Amavasya is Naga. The next month begins again with Kimstughna.
Because of this pattern, you can find the Karana from the Tithi alone. A good Panchang lists the Karana with start and end times, so you do not need to count.
Qualities of the Karanas
The six movable Karanas other than Vishti are generally treated as favorable.
Bava. Good for steady and constructive work. Balava. Good for religious acts and study. Kaulava. Good for friendship and shared tasks. Taitila. Good for property and domestic matters. Gara. Good for farming and building. Vanija. Good for trade and commerce.
The fixed Karanas are generally treated as unfavorable for new work, as they fall around the new Moon, a time of low light. They are Shakuni, Chatushpada, Naga and Kimstughna.
Vishti, also called Bhadra
Vishti is the best known Karana, and the one most often avoided. It is also called Bhadra. It occurs eight times in a lunar month, and each period lasts for several hours. Traditional guidance is to avoid starting new, auspicious work during Bhadra, such as a wedding, a housewarming or a business opening. Some practices are done after it ends. The best known is the tying of the sacred thread of Raksha Bandhan, where families wait until Bhadra has passed.
Bhadra has exceptions. Some texts say that it has less effect depending on where the Moon is and which part of the period you are in. Some rituals, such as those aimed at removing enemies, are said to be fit for it. A good Panchang shows the start and end time of Bhadra for your city, so that you can plan around it.
How Karana is used
People who follow the Panchang look at the Karana last, after the Tithi and Nakshatra. When setting a date, they prefer a window with a favorable Karana and avoid Vishti. For most people the Karana is a small detail, and the Tithi gives the larger picture. See What is Tithi?.
Because a Karana is short, it is useful for fine timing within a day. If a wedding is set for a day that has Bhadra in the morning, the family may choose the afternoon, after the Karana has changed. Taken together with the weekday time windows, such as Rahu Kala and the Choghadiya, it helps to find a quiet window.
Karana and the other limbs
The five limbs form a set. A well chosen time has a favorable Tithi, a suitable Nakshatra, a good Yoga and a good Karana. In practice few moments satisfy all five, so tradition weights some more than others. Many families give most weight to the Tithi and the Nakshatra, and use the Karana and the Yoga to rule out clearly poor periods.
A word of balance
Scientific studies have not shown that the Karana influences the outcome of an event. It is part of a cultural calendar. If you live outside India and do not follow the tradition, you can safely ignore it. If you do follow it, treat the Karana as one guide among several and not as a reason to delay a decision.