The 12 lunar months in the classical Vedic/Hindu lunisolar calendar are the following Sanskrit lunar months, each aligned to one full synodic cycle of the Moon (≈29.5 days). These months are attested across standard Panchāṅgas and described in contemporary sources.
The 12 Lunar Months (Amānta & Pūrṇimānta Systems)
| # | Sanskrit Month | Approx. Gregorian Span | Key Notes |
|---|---|---|---|
| 1. Chaitra | March–April | Begins the New Year in many regions; linked with spring. | |
| 2. Vaishākha | April–May | Considered highly auspicious; Akshaya Tritiya occurs here. | |
| 3. Jyeṣṭha | May–June | Peak summer; associated with heat and discipline. | |
| 4. Āṣāḍha | June–July | Monsoon begins; Devshayani Ekadashi marks Vishnu’s Yoga-Nidra. | |
| 5. Śrāvaṇa | July–August | Sacred month for Shiva; includes Raksha Bandhan & Janmashtami. | |
| 6. Bhādrapada | August–September | Ganesh Chaturthi and Anant Chaturdashi fall here. | |
| 7. Āśvina | September–October | Navratri, Durga Puja, Dussehra. | |
| 8. Kārtika | October–November | Considered the holiest month; Diwali occurs here. | |
| 9. Mārgaśīrṣa | November–December | Vaikuntha Ekadashi; winter begins. | |
| 10. Pauṣa | December–January | Deep winter month. | |
| 11. Māgha | January–February | Named after the Maghā Nakshatra; includes Magha Purnima. | |
| 12. Phālguna | February–March | Ends the lunar year; Holi is celebrated. |
How the Lunar Month Is Defined
- A lunar month is one complete cycle of the Moon’s phases (~29.5 days).
- Two systems exist:
- Amānta: Month begins the day after Amāvasyā (New Moon).
- Pūrṇimānta: Month begins the day after Pūrṇimā (Full Moon).
- Both systems contain the same 12 months; only the boundary differs – Amānta starts with waxing half (Shukla) while Pūrṇānta starts in waning half
Why 12 Lunar Months?
- Twelve synodic lunar cycles ≈ 354 days, forming the lunar year.
- To align with the solar year (~365 days), an adhika māsa (extra month) is inserted every 32–33 months.