Tithi is the angular distance between the Sun and Moon, measured in units of 12°. There are 30 tithis in a lunar month – 15 in the waxing half (Shukla Paksha, from New Moon to Full Moon) and 15 in the waning half (Krishna Paksha, from Full Moon to New Moon). Each tithi has a specific name (Pratipada, Dwitiya, Tritiya... Chaturdashi, Purnima/Amavasya) and a ruling deity. Tithis are not equal to solar days – a tithi can last from about 19 hours to 26 hours depending on the Moon's speed in its elliptical orbit. A tithi that is current at sunrise governs the entire Vedic day. If a tithi starts after sunrise and ends before the next sunrise, it is called a 'Kshaya Tithi' (lost tithi); if the same tithi spans two sunrises, it is 'Vriddhi' (extended).

Nakshatra refers to the Moon's position among the 27 constellations that divide the ecliptic into segments of 13°20' each. The Moon transits one nakshatra roughly every day (about 24 hours), giving each day a distinct 'stellar signature'. Each nakshatra has a ruling planet, deity, symbol, and set of qualities. The nakshatra is the primary factor in muhurta selection – more important than tithi or weekday. In daily life, the nakshatra governs the spiritual and psychological quality of the day: Pushya (the most auspicious) is excellent for new beginnings; Ashlesha brings intensity and transformation; Revati is gentle and ideal for travel.

Yoga in Panchang (not to be confused with planetary yogas in Kundali) is calculated by adding the longitudes of the Sun and Moon, then dividing by 13°20'. There are 27 yogas in total, cycling through the month. Each yoga has a name and character: Siddhi yoga is excellent for accomplishments; Vishkambha is obstructive; Shubha is auspicious; Vridhi brings growth. Some yogas like Vyatipata and Vaidhriti are considered especially inauspicious and are traditionally avoided for important activities. The yoga changes roughly every 24 hours but can vary based on the relative speeds of the luminaries.

A Karana is half a tithi – each tithi has two karanas, so there are 60 karanas in a lunar month. There are 11 named karanas: 7 'movable' (Chara) karanas that repeat 8 times each (Bava, Balava, Kaulava, Taitila, Gara, Vanija, Vishti) and 4 'fixed' (Sthira) karanas that occur only once per month (Shakuni, Chatushpada, Naga, Kimsthughna). The most important karana for daily use is Vishti (also called Bhadra) – it recurs every 7 tithis and is considered highly inauspicious. No important activity should be started during Vishti Karana. The fixed karanas Shakuni, Chatushpada, and Naga are also inauspicious.

Vara is the simplest of the five elements – it is the weekday, from Sunday to Saturday, each ruled by one of the seven visible planets. The Vedic day begins at sunrise (not midnight), so the vara changes at sunrise. Each vara has a ruling planet: Ravivara (Sunday – Sun), Somvara (Monday – Moon), Mangalvara (Tuesday – Mars), Budhvara (Wednesday – Mercury), Guruvara (Thursday – Jupiter), Shukravara (Friday – Venus), Shanivara (Saturday – Saturn). The vara lord influences the day's character: Tuesday is Mars-ruled and favourable for courage, surgery, and competition; Thursday is Jupiter-ruled and excellent for learning, rituals, and spiritual activities.

A fundamental difference between the Vedic Panchang and the modern Gregorian calendar is when the day begins. In the Panchang, the day starts at sunrise, not at midnight. This means the tithi, nakshatra, yoga, and karana that are active at sunrise govern the entire Vedic day – even if they change later. If Ekadashi begins at 3 AM (before sunrise), the Vedic day is still governed by the previous day's tithi until sunrise. This sunrise-based system is why Panchang requires your exact geographic location: sunrise time varies by latitude and longitude, so the same moment in time can belong to different Vedic days in different cities.

The Vedic lunar month can be counted two different ways, leading to two parallel systems. In the Amanta (also called Amavasyant) system used primarily in South and West India (Maharashtra, Gujarat, Karnataka, Tamil Nadu), the month ends on Amavasya (New Moon). In the Purnimanta system used in North India, the month ends on Purnima (Full Moon). During Shukla Paksha (waxing Moon), both systems agree on the month name. But during Krishna Paksha (waning Moon), the Purnimanta month is one name ahead of the Amanta month. For example, Krishna Paksha of Chaitra (Amanta) is the same as Krishna Paksha of Vaishakha (Purnimanta). This difference explains why the same festival sometimes appears under different month names in different regional panchangas. Both systems are equally valid – they simply count the boundary differently.

You don't need to be an astrologer to benefit from the Panchang. Here are practical daily applications: (1) Check the tithi for fasting – Ekadashi (11th tithi) is the primary fasting day; Chaturthi (4th) for Ganesh worship; Purnima and Amavasya for specific rituals. (2) Check for inauspicious periods – avoid starting important work during Rahu Kaal, Yamaganda, or Vishti Karana. (3) Use the nakshatra for major decisions – Pushya, Rohini, Hasta, and Shravana are universally auspicious; avoid Ashlesha, Ardra, and Mula for new beginnings. (4) Check the yoga – avoid Vishkambha, Vyatipata, and Vaidhriti for auspicious work. (5) Match the weekday – Tuesday and Saturday are generally avoided for new ventures; Thursday and Friday are considered favourable.