See also: Astronomical basis of the Hindu calendar. Paksha (Sanskrit: पक्ष|translit=pakṣa) refers to a fortnight or a lunar phase in a month of the Hindu lunar calendar.[1] [2]
Literally meaning "side",[3] a paksha is the period either side of the purnima (full moon day). A lunar month in the Hindu calendar has two fortnights, and begins with the purnima (new moon). The lunar days are called tithis; each month has 30 tithis, which may vary from 20 – 27 hours. A paksha has 15 tithis, which are calculated by a 12 degree motion of the moon. The first fortnight between the new moon day and the full moon day is called the Gaura Paksha or Shukla Paksha, the period of the brightening moon (waxing moon), and the second fortnight of the month is called the Vadhya Paksha or Krishna Paksha, the period of the fading moon (waning moon).[1] [4] The Neemuch calendar begin a new lunar month from first day of Krishna Paksha, while the Gujarat calendar begins a new lunar month from the first day of Shukla Paksha.
| Shukla Paksha | Krishna Paksha | |
|---|---|---|
| 1. Prathama | 1. Prathama | |
| 2. Dvitiya | 2. Dvitiya | |
| 3. Tritiya | 3. Tritiya | |
| 4. Chaturthi | 4. Chaturthi | |
| 5. Panchami | 5. Panchami | |
| 6. Shashti | 6. Shashti | |
| 7. Saptami | 7. Saptami | |
| 8. Ashtami | 8. Ashtami | |
| 9. Navami | 9. Navami | |
| 10. Dashami | 10. Dashami | |
| 11. Ekadashi | 11. Ekadashi | |
| 12. Dwadashi | 12. Dwadashi | |
| 13. Thrayodashi | 13. Thrayodashi | |
| 14. Chaturdashi | 14. Chaturdashi | |
| 15. Purnima | 15. Amavasya, Ausi |
Shukla Paksha refers to the bright lunar fortnight or waxing moon in the Hindu calendar. Shukla (Sanskrit: शुक्ल) is a Sanskrit word for "white" or "bright". The Shukla Paksha is a period of 15 days, which begins after the amavasya (new moon) day and culminating on purnima (full moon) day and is considered auspicious.[5]
Numerous festivals are held during this period, including the Navaratri festivals, most importantly Chaitra Navaratri and Ashvin Navaratri.
| Day | Tithi | class=unsortable | Festival | Month |
|---|---|---|---|---|
| 1st day | Pratipada | Gudi Padwa, Ugadi | Chaitra | |
| 1st day | Pratipada | Bali Pratipada, Govardhan Puja | Kartika | |
| 2nd day | Dvitiya | Bhaibeej | Kartika | |
| 3rd day | Tritiya | Teej | Bhadrapada | |
| 3rd day | Tritiya | Akshaya Tritiya | Vaishakha | |
| 4th day | Chaturthi | Ganesh Chaturthi | Bhadrapada | |
| 4th day | Chaturthi | Ganesh Jayanti | Magha | |
| 5th day | Panchami | Nuakhai | Bhadrapada | |
| 5th day | Panchami | Vivaha Panchami | Margashirsha | |
| 5th day | Panchami | Vasanta Panchami | Magha | |
| 6th day | Shasthi | Sitalsasthi | Jyestha | |
| 8th day | Ashtami | Radhashtami | Bhadrapada | |
| 9th day | Navami | Rama Navami | Chaitra | |
| 10th day | Dashami | Vijayadashami | Ashvin | |
| 11th day | Ekadashi | Shayani Ekadashi | Ashadha | |
| 11th day | Ekadashi | Vaikuntha Ekadashi | Margashirsha | |
| 14th day | Chaturdashi | Samvatsari | Bhadrapada | |
| 15th day (full moon) | Purnima | Guru Purnima | Ashada |
Krishna Paksha refers to the dark lunar fortnight or waning moon in the Hindu calendar. Krishna (Sanskrit: कृष्ण) is a Sanskrit word for "dark". Krishna Paksha is a period of 15 days, which begins after purnima day (full moon), culminating on the amavasya (new moon). Krishna Paksha is considered inauspicious,[6] as the moon loses light during this period.
Festivals during the Krishna Paksha are:
| Day | Tithi | class=unsortable | Festival | Month |
|---|---|---|---|---|
| 4th day | Chaturthi | Karva Chauth | Kartika | |
| 8th day | Ashtami | Krishna Janmashtami | Bhadrapada | |
| 13th day | Thrayodashi | Dhanteras | Kartika | |
| 13th day | Thrayodashi | Pradosha | Magha | |
| 14th day | Chaturdashi | Maha Shivaratri | Magha | |
| 14th day | Chaturdashi | Naraka Chaturdashi (Diwali) | Kartika | |
| 15th day (no moon) | Amavasya | Lakshmi Puja (Diwali) | Kartika |
In Vedic astrology when a person does a prasna (a question chart) and the planet Venus indicates the time period, the event referred to in the answer will happen in a pakṣa (fortnight) from the time the question was asked.