The tithi is the lunar day, the first and most important limb of the panchang. Almost every Hindu festival and fast is fixed by tithi rather than by the solar calendar, which is why Diwali or Ekadashi fall on different dates each year.
How a tithi is calculated
A tithi is the time it takes the Moon to gain 12° on the Sun. At Amavasya (new moon) the two are together; at Purnima (full moon) they are 180° apart. 360° divided by 12° gives 30 tithis in a lunar month:
- Shukla paksha (bright, waxing half): Pratipada (1st) to Purnima (15th).
- Krishna paksha (dark, waning half): Pratipada to Amavasya (the 30th).
Because the Moon's speed varies, a tithi lasts anywhere from about 19 to 26 hours. Occasionally a tithi begins and ends between two sunrises and is "skipped" in the calendar (kshaya), or spans two sunrises and is counted twice (adhika). The tithi prevailing at sunrise usually names the day.
The five groups
The tithis repeat in a cycle of five, each with a character:
| Group | Tithis | Nature |
|---|---|---|
| Nanda (joy) | 1, 6, 11 | Good for celebrations and pleasant beginnings |
| Bhadra (auspicious) | 2, 7, 12 | Good for steady, constructive work |
| Jaya (victory) | 3, 8, 13 | Good for overcoming obstacles, competition |
| Rikta (empty) | 4, 9, 14 | Avoided for auspicious beginnings |
| Purna (full) | 5, 10, 15 | Good for completion and most auspicious work |
The Rikta tithis, Chaturthi, Navami and Chaturdashi, are widely avoided for weddings, griha pravesh and new ventures. Amavasya is also avoided for most beginnings, though it is important for honouring ancestors.
Important tithis
- Ekadashi (11th), twice a month: a day of fasting and devotion to Vishnu.
- Pradosha, around the 13th, at dusk: worship of Shiva.
- Chaturthi (4th): Ganesha, especially Sankashti Chaturthi in the dark half.
- Purnima: Satyanarayana puja, many festivals, and lunar eclipses.
- Amavasya: ancestors (pitru tarpan), and solar eclipses.
Tithis in muhurta
For a wedding muhurta, the 2nd, 3rd, 5th, 7th, 10th, 11th and 13th of the bright half are generally preferred. For most beginnings the bright half is preferred over the dark half, as the Moon's light grows.
Your birth tithi
The tithi of your birth (janma tithi) is used for traditional birthday observances and adds a layer to the chart: it describes the relationship between your Sun and Moon.
See today's tithi, with its exact end time for your city, on our panchang.