Karanaकरण
Karana is half of a Tithi — since there are 30 Tithis in a lunar month and each splits into two Karanas, there are 60 Karana instances per month, cycling through 11 named Karanas (7 of which repeat, 4 of which occur only once per month).
Karanas carry their own auspicious/inauspicious character, traditionally used alongside Tithi for fine-tuning Muhurta selection — a full treatment of which Karana suits which activity is beyond a quick-reference glossary entry.
Each Karana spans exactly half a Tithi (~9–13 hours, following the same variable-duration logic as Tithi).
There are 11 Karanas in total. 7 are "repeating" (Chara) — they cycle through the lunar month: Bava, Balava, Kaulava, Taitila, Garaja, Vanija, Vishti (also called Bhadra). 4 are "fixed" (Sthira) — they occur only once each month at specific positions: Kimstughna (start of Shukla Paksha), Shakuni, Chatushpada, Naga (end of Krishna Paksha). This app uses exactly this scheme.
Of the 7 repeating Karanas, Vishti (Bhadra) is the most widely observed inauspicious one — traditionally avoided for starting new work, travel, or ceremonies. The others (Bava, Balava, Kaulava, Taitila, Garaja, Vanija) are generally considered neutral to auspicious, with Bava and Balava being the most favorable for important beginnings.