What is Panchang?

Panchang (or Panchanga) is a Sanskrit word derived from Pancha (five) and Anga (limbs/parts). So Panchang means "Five Limbs" — and it refers to five key elements that help in calculating the auspicious and inauspicious timings in Vedic timekeeping.

]The Five Parts of Panchang

Tithi (तिथि) – Lunar Day

A Tithi is the time it takes for the longitudinal angle between the Moon and the Sun to increase by 12 degrees.

There are 30 Tithis in a lunar month:

15 during Shukla Paksha (waxing moon)
15 during Krishna Paksha (waning moon)

Examples: Pratipada, Dwitiya, Tritiya, etc.

Vaar (वार) – Day of the Week

These are the seven days of the week: Ravi (Sunday), Soma (Monday), etc.

Each day is ruled by a planet.

Nakshatra (नक्षत्र) – Lunar Mansion

The Moon travels through 27 (sometimes 28) Nakshatras or constellations.

Each Nakshatra has its own attributes and ruling deity.

Examples: Ashwini, Bharani, Krittika, Rohini, etc.

Yoga (योग) – Planetary Combination

27 Yogas are calculated based on the sum of the Sun and Moon's positions.

Each Yoga has auspicious or inauspicious implications.

Examples: Vishkumbha, Preeti, Ayushman, etc.

Karana (करण) – Half of a Tithi

Each Tithi has two Karanas (first half and second half).

There are 11 Karanas in total (4 fixed and 7 recurring).

Examples: Bava, Balava, Kaulava, Taitila, etc.

For more details: https://vedicmeet.com/astrology/panchang