A full month of the Hindu calendar on one screen: seven columns, one cell per civil day, each carrying its tithi and the clock time that tithi ends, its nakshatra, its paksha, and any festival or vrat dated to it. Choose your city and the whole month is recomputed, because the Hindu day begins at sunrise and sunrise is local. Where the classical texts support more than one date, every one of them is shown.
Most Hindu calendars online are really day lookups: you choose a date and get one day back. That answers 'what is the tithi today', but not the question people actually open a calendar for - when in this month does Ekadashi fall, how many days until Purnima, is the festival on a weekend.
This page is the month. The grid runs Sunday to Saturday like any wall calendar, and each cell adds the two things a Gregorian calendar cannot tell you: which tithi the day belongs to, and when that tithi lets go. Tap or arrow to any day for its full detail, and open the daily panchang when you need that day's muhurtas, choghadiya and Rahu Kaal.
The same lunar month has two names depending on where you are. In the amanta reckoning of the south and west, the month ends at the new moon; in the purnimanta reckoning of the north, it ends at the full moon. Sewell and Dikshit put the consequence plainly in The Indian Calendar (1896), Art. 51: the bright fortnights carry the same name in both schemes, the dark fortnights differ by a whole month, and so the purnimanta scheme is always a fortnight ahead.
That is why a festival is described as falling in Ashwin by one almanac and Kartik by another, with no disagreement about the actual day. This calendar prints both bands over the month and both names on every day, so you can read whichever your family uses without having to convert.
Ekadashi is the clearest case. Kane's History of Dharmasastra V.i pp.113-115 records that the Smarta reckoning is affected by suryodaya-vedha alone, while the Vaishnava reckoning is also affected by arunodaya-vedha: if Dashami persists into the last four ghatikas before sunrise, that Ekadashi is rejected for the Vaishnava and the fast moves to the next day. Several times a year the two land on different civil days.
Navaratra is another. Kane p.154 quotes the Tithitattva giving seven alternative Durgapuja periods and adds that most of them find support in the Kalika and other Puranas. And for a handful of festivals the sources simply do not settle the civil day at all - Kane names the loci for the Divali tie-break at p.198 and then writes that it 'is passed over here'.
Almost every calendar quietly picks one of these and prints it. This one marks the day, shows every date the texts support, and names the rule and the text behind each. Nothing is labelled the main day, the primary date or the recommended one, because no source ranks them.
A tithi is the time the Moon takes to gain 12 degrees on the Sun, which runs anywhere from about 19 to 26 hours - so it does not line up with a 24-hour day. When a tithi is long it can cover two sunrises and its number is counted twice (vriddhi). When it is short it can begin after one sunrise and end before the next, touching no sunrise at all, and its number is skipped entirely (kshaya).
Both are marked here. A skipped tithi is worth seeing rather than silently omitting: when the skipped one is Ekadashi or Chaturthi, an observance you were expecting to find in the month may genuinely not have a day of its own that lunation.
The Hindu civil day runs from sunrise to sunrise, and the tithi assigned to a day is the one prevailing at that sunrise. Sunrise moves with longitude and latitude, so a tithi ending in the early morning belongs to one day in Chennai and the next in Delhi - and the festival built on it moves with it.
This calendar therefore takes a city, not a country. Sun and Moon positions are computed to sub-arcsecond precision with the Lahiri ayanamsha, and every tithi and nakshatra boundary is solved for the exact instant rather than estimated at a mean rate.
This is the month; the daily panchang is the day. The grid gives you every day's tithi, nakshatra, vara, paksha, festivals and vrats at once, so you can plan across weeks. The daily panchang gives one day in full depth - muhurtas, choghadiya, Rahu Kaal, yoga, karana and the auspicious windows. Use the grid to find the day, then open the day view.
Because two reckonings of the lunar month are both in use. The amanta month ends at the new moon and the purnimanta month at the full moon, so during a dark fortnight the same day sits in Ashwin by one scheme and Kartik by the other. Sewell and Dikshit, The Indian Calendar Art. 51, state that the purnimanta scheme is always a fortnight ahead. Both names are shown so neither region's usage is assumed.
Because the Smarta and Vaishnava traditions date it by different rules. Kane, History of Dharmasastra V.i pp.113-115, records that the Smarta is affected by suryodaya-vedha only while the Vaishnava is also affected by arunodaya-vedha, so when Dashami runs into the last four ghatikas before sunrise the Vaishnava fast moves to the next day. Both dates are shown, each labelled with its lineage.
Yes, and it should. The Hindu day runs from sunrise to sunrise and the day's tithi is the one prevailing at that sunrise, so a tithi that ends in the early morning belongs to different civil days in different cities. Pick your city and the whole month is recomputed for it, including the festival and vrat dates that depend on it.
A tithi is the time the Moon takes to gain 12 degrees on the Sun and lasts about 19 to 26 hours. If it is long enough to cover two sunrises, its number repeats on two civil days - that is vriddhi. If it is short enough to begin after one sunrise and end before the next, no civil day carries its number - that is kshaya, and the calendar shows it in the day panel so a missing observance is explained rather than silently dropped.
The festivals and recurring vratas the engine can date from a named classical rule - Ekadashi in both lineages, Pradosh, Sankashti and Vinayaka Chaturthi, Purnima and Amavasya, Durgashtami, Navaratra and Durgapuja in their several Tithitattva periods, the Divali sequence, Shivaratri, Janmashtami, the solar sankranti festivals and more. Each carries the division of the day it was dated on and the text that rule comes from.
For educational purposes. Astrological interpretations are traditional and not a substitute for professional advice.