Vishti is the seventh and last of the movable (chara) karanas, but it is set apart from the other six by its inauspicious character. Also called Bhadra, it is personified in tradition as a fierce goddess, and the almanac treats the period it governs as unfavourable, auspicious ceremonies, journeys, and new undertakings are avoided while Vishti or Bhadra is in force, and manuals give rules for reckoning when it falls by day or by night. Despite the name Bhadra, which can mean auspicious, its practical reputation in the panchanga is the opposite, and it is the one recurring karana singled out for caution. It recurs eight times through the month like the other movable karanas. These are the conventions of the calendar tradition, in which Vishti is the recurring half-tithi to be worked around.
Classical sources give Vishti a presiding deity, Yama, the god of death and of dharma, and a planetary association with Shani, Saturn, the harshest of the classical malefics, and this double attribution is generally offered as the explanation for why the karana carries such a consistently unfavourable reputation across the muhurta tradition when every other karana, fixed or movable, is read as at least mildly favourable or neutral. Because Vishti recurs eight times through the month like the other movable karanas but is avoided for auspicious activity every time it falls, contemporary Indian almanacs and panchang mobile applications commonly publish a running calendar of Bhadra timings specifically, distinct from the general tithi and karana tables, so that the inauspicious half-tithi can be checked and avoided without consulting the full panchanga.