The signature feature
How regions differ
A region on this site is not a language toggle. It is a bundle of eleven independent conventions, and getting any one of them wrong produces a calendar that is confidently and invisibly wrong for that reader.
| # | Axis | Variation | Consequence if wrong |
|---|---|---|---|
| 1 | Lunar month convention | Amanta (ends at Amavasya) vs Purnimanta (ends at Purnima) | Every Krishna-paksha festival carries the wrong month name. Maha Shivaratri is Magha K-14 in Amanta and Phalguna K-14 in Purnimanta — the same day, a different label. |
| 2 | Era / samvat displayed | Vikram (Chaitra-start), Vikram (Kartika-start, Gujarat), Shaka, Kollam, Bengali San, Bikram Sambat, Gaurabda | The year number on the page is simply wrong for that reader. |
| 3 | 60-year Samvatsara | Southern and Northern reckonings of the Jovian cycle can differ by one name | The samvatsara recited in the sankalpam is wrong. |
| 4 | New year day | Ugadi · Gudi Padwa · Bestu Varas · Puthandu · Vishu · Poila Boishakh · Bohag Bihu · Navreh · Vaisakhi | The year rolls over on the wrong date, so every year view is off. |
| 5 | Solar overlay | Tamil, Malayalam, Bengali, Odia and Assamese calendars are solar-primary; the tithi is an overlay | Chithirai / Chingam / Boishakh month names and civil dates are missing entirely. |
| 6 | Sankranti transfer rule | Tamil (sunset rule), Kerala (aparahna rule), Bengal (midnight-ish rule) | The solar month starts a day early or late. |
| 7 | Ayanamsa / siddhanta | Drik ganita with Lahiri is mainstream; Raman and KP exist; Vakya is still followed in parts of Tamil Nadu | Tithi end-times shift by a few ghatikas, and some festival days move by a day. |
| 8 | Festival observance rule | Vat Savitri, Deepavali, Navratri emphasis, Karva Chauth, Chhath, Onam, Pongal, Bihu | Readers see days they do not observe and miss the ones they do. |
| 9 | Muhurta system shown | Choghadiya (North/West) · Gowri Panchangam and Nalla Neram (Tamil) · Rahu Kalam, Varjyam, Durmuhurtam (Telugu/Kannada) · Hora | The page shows a timing system the reader’s family does not use. |
| 10 | Language and script | Twelve-plus scripts; and separately, transliteration — a Sanskrit sankalpam in Telugu letters is not a Telugu translation | Silent font fallback destroys conjuncts; machine translation destroys liturgical text. |
| 11 | Location and timezone | Sunrise-based tithi means every value depends on latitude and longitude; the diaspora adds DST | A Telugu family in Toronto gets Hyderabad’s rahu kalam. This is the single most common real-world failure. |
Presets shipping now
| Preset | Months | New year | Muhurta | Practitioner sign-off |
|---|---|---|---|---|
| Andhra & Telangana ఆంధ్ర · తెలంగాణ |
amanta | Ugadi (Chaitra Shukla Pratipada) | rahu, varjyam, durmuhurtam, gowri | not yet reviewed |
| Karnataka ಕರ್ನಾಟಕ |
amanta | Yugadi (Chaitra Shukla Pratipada) | rahu, gowri, varjyam | not yet reviewed |
| Maharashtra & Goa महाराष्ट्र · गोवा |
amanta | Gudi Padwa (Chaitra Shukla Pratipada) | choghadiya, rahu | not yet reviewed |
| Gujarat ગુજરાત |
amanta | Bestu Varas (Kartika Shukla Pratipada) | choghadiya | not yet reviewed |
| North India उत्तर भारत |
purnimanta | Chaitra Shukla Pratipada | choghadiya, rahu | not yet reviewed |
| International (English) International |
amanta | Chaitra Shukla Pratipada | rahu, choghadiya, gowri, varjyam, durmuhurtam | not yet reviewed |
No preset here has been signed off yet. Every row must be
confirmed by a practitioner of that tradition before it can be called correct. Until then the
arithmetic is sound and the conventions are our reading of them — check any date that matters
against your family almanac, and tell us where we are wrong.
Specified, not yet shipped
| Preset | What it still needs | Target | ||
|---|---|---|---|---|
| Tamil Nadu | Solar-primary — needs the Chithirai–Panguni overlay and the sunset sankranti rule | v1.5 | ||
| Kerala | Solar-primary — Kollam era, Chingam–Karkidakam, aparahna sankranti rule | v1.5 | ||
| Bengal | Purnimanta lunar over a solar civil calendar; Bengali San | v1.5 | ||
| Odisha | Anka reckoning over solar civil months | v2 | ||
| Assam | Bohag Bihu, Bengali San / Shaka | v2 | ||
| Punjab | Nanakshahi alongside Vikram | v2 | ||
| Nepal | Bikram Sambat, Baisakh 1 | v2 | ||
| Gaudiya / ISKCON | Gaurabda era, Ekadashi parana windows | v2 | ||
Why the month name changes but the day does not
An amanta month ends at the new moon; a purnimanta month ends at the full moon. Both traditions agree exactly on when the tithi begins and ends — the astronomy is the same. What differs is only where the month boundary is drawn, so a Krishna-paksha day carries the next month’s name in the North and the current month’s name in the South.
Every Shukla-paksha day matches in both systems. That is why the “in other regions” card on the daily page appears on some days and not others: it is shown when something genuinely differs, and absent when nothing does.