Vanija is the sixth karana and the sixth of the seven movable (chara) karanas, recurring eight times through the lunar month. Its name means the merchant, and the almanac tradition accordingly associates it with trade, commerce, and profitable transactions, a karana favourable for buying, selling, and business ventures. As one of the moving karanas it is generally read as benefic in the panchanga. Like the others it forms one of the five daily limbs of the Hindu almanac, refining the tithi by distinguishing its two halves. These are the conventions of the calendar tradition, in which each named karana carries a traditional character that an astrologer consults when timing an activity to suit its nature, here, matters of the marketplace.
The mercantile reading of Vanija reflects a broader pattern in Indian electional astrology, in which merchants historically consulted an astrologer or a printed panchanga before opening a new venture, signing an agreement, or setting out on a trading journey, a practice still followed by some business owners in India today when choosing a date to register a company or open new premises. Vanija's position as the sixth of the seven movable karanas places it immediately before Vishti, the one karana of the eleven singled out for its unfavourable reputation, so that in the continuous rotation of the movable karanas a favourable mercantile half-tithi is always immediately followed by the karana every muhurta manual instructs the astrologer to avoid.