Amrutkaal Paksha: The Two Halves of the Lunar Month
The Hindu month is lunar: roughly 29½ days from new moon to new moon, split into two pakshas (fortnights). Shukla Paksha — the bright half — runs from Amavasya to Purnima as the Moon waxes; Krishna Paksha — the dark half — runs from Purnima back to Amavasya. Most observances are anchored to a paksha: Ekadashi fasts come once per paksha, Navratri opens Shukla Pratipada, Janmashtami falls on Krishna Ashtami.
Purnimanta vs Amanta — one calendar, two labels
North India follows the purnimanta convention: a month ENDS at Purnima, so the Krishna Paksha that follows the full moon belongs to the NEXT month. South and West India follow amanta: a month ends at Amavasya, keeping both pakshas of one lunation in the same month. The days themselves are identical everywhere — only the month label of the dark fortnight differs. This is why Diwali is "Kartika Amavasya" in the North but "Ashvina Amavasya" in amanta reckoning, and why month-named festivals can look like they disagree across regions when they are the same day.
Adhika Masa — the leap month
Twelve lunar months are about 354 days — 11 short of the solar year. To stay aligned with the seasons, the calendar inserts an extra month (Adhika Masa) roughly every 32½ months: a lunar month in which the Sun does not enter a new sign. The inserted month takes its neighbour's name with "Adhika" prefixed, and festivals wait for the regular (nija) month. This is why festival dates swing across a five-week range from year to year — and occasionally jump 19 days later instead of 11 days earlier.
Reading paksha in daily life
The waxing half is conventionally preferred for growth-beginnings — marriages, housewarmings, new enterprises — with the Moon gaining strength. The waning half suits completion, reflection and ancestor rites: Pitru Paksha, the fortnight of remembrance, is the Krishna Paksha of Bhadrapada/Ashvina. Neither half is "bad"; they carry different work.
Frequently Asked Questions
Which paksha is running today?
Check your city's panchang page on this site — the paksha and tithi headline every page. Shukla if the Moon is waxing toward full, Krishna if waning toward new.
Is Krishna Paksha inauspicious?
No. It is preferred for different purposes — endings, clearing, ancestor rites — and several major festivals (Janmashtami, Diwali, Maha Shivaratri) fall in Krishna Paksha. The first few and last few tithis of the dark half are simply avoided for big beginnings by convention.
What is Pitru Paksha?
The 16-day ancestor fortnight — Bhadrapada Purnima through Ashvina Amavasya (purnimanta naming) — when shraddha rites are performed. New ventures are traditionally paused; it ends with Sarva Pitru Amavasya, after which Navratri begins.