What Is the Hindu Calendar? Complete Guide to Panchang, Tithis & Lunar Timekeeping
The Hindu Calendar, commonly known as the Panchang, is one of the oldest and most sophisticated time-keeping systems in the world. It is a lunisolar system that aligns lunar phases with the Sun’s movement, guiding festivals, rituals, agricultural cycles, and daily observances across India.
What Is the Hindu Calendar?
The Hindu Calendar (Panchang) is traditionally used to determine festival dates, vrats (fasting days), auspicious timings, and religious observances. Its calculations rely on three major components:
- The lunar cycle — determines months.
- The solar position — determines seasons.
- The combined lunar–solar system — determines tithis, nakshatras, and muhurta.
This lunisolar structure forms the foundation for regional calendars such as the Vikram Samvat, which is widely used in many parts of India.
Hindu Calendar vs. Gregorian Calendar
The primary difference between the Hindu and Gregorian calendars is calculation method. The Gregorian calendar is purely solar with fixed month lengths, whereas the Hindu calendar follows the Moon’s movement. Hindu months therefore vary slightly in length (about ~29.5 days) and shift relative to the Gregorian calendar, making festival dates based on tithis rather than fixed Gregorian dates.
Hindu Calendar Months
The Hindu calendar includes twelve lunar months:
Chaitra, Vaishakha, Jyeshtha, Ashadha, Shravan, Bhadrapada, Ashwin, Kartik, Margashirsha, Pausha, Magha, Phalguna.
Across India, month beginnings follow two systems:
- Amanta System (New Moon) — followed in South India, Gujarat, and Maharashtra.
- Purnimanta System (Full Moon) — followed in North India.
Although naming and month boundaries can differ slightly regionally, Panchang calculations for tithis and nakshatras remain consistent in principle.
Understanding Tithis, Pakshas, and Nakshatras
Each lunar month is divided into two phases known as pakshas:
- Shukla Paksha — begins the day after Amavasya (New Moon) and continues until Purnima (Full Moon); this is the bright, waxing phase.
- Krishna Paksha — begins the day after Purnima and continues until Amavasya; the dark, waning phase.
A lunar month contains 30 tithis (lunar days). Tithis are central to determining festival dates, fasts, and auspicious timings. The Panchang also uses 27 nakshatras (lunar constellations) that are key to Vedic astrology and rituals such as marriage muhurta and temple ceremonies.
Why the Hindu Calendar Matters Today
Despite the widespread daily use of the Gregorian calendar, the Hindu calendar guides millions in religious and cultural life. Temple rituals, festival observances, marriage muhurta, housewarmings, and even traditional agricultural planning follow the Panchang. It connects people to natural rhythms and seasonal cycles.
How the Hindu Calendar Shapes Festivals
Many Hindu festivals are determined by tithis rather than fixed Gregorian dates, so their calendar dates shift from year to year. Notable examples include:
- Diwali — Amavasya (New Moon)
- Holi — Purnima (Full Moon)
- Navratri — Shukla Paksha Pratipada (first day of the bright fortnight)
- Janmashtami — Ashtami (eighth lunar day)
- Mahashivratri — Chaturdashi (fourteenth lunar day)
This dynamic system reflects the natural ebb and flow of the lunar cycle.
Vikram Samvat and the Hindu Calendar
The Vikram Samvat uses the same Panchang principles but counts years from the era of King Vikramaditya. It runs approximately 56–57 years ahead of the Gregorian calendar depending on month; e.g., Vikram Samvat 2083 corresponds roughly to Gregorian 2026–27. While year counts differ, tithis, nakshatras, and festival calculations follow the same lunisolar rules.