What is the difference between Udaya Tithi and the astronomical tithi?

The astronomical tithi is a continuous 12-degree slice of Moon-Sun elongation that runs its course at any clock hour. The Udaya Tithi convention — used across most North Indian panchangs and this page — dates a calendar day by whichever tithi is current at local sunrise. Some southern and Telugu traditions instead key certain observances to the tithi prevailing at other anchors such as sunset (Pradosh) or moonrise (Sankashti).

Can two tithis occur on the same calendar day?

Yes. When a long tithi spans two consecutive sunrises (a vriddhi tithi), the same lunar day is current on two calendar dates. The reverse also happens: a short tithi can begin after one sunrise and end before the next (a kshaya tithi), skipping a lunar day entirely — these dates are marked (kshaya) in this site’s tables.

Why does the tithi end time matter more than the tithi name?

Observances are kept while the tithi is current, so the end moment decides how much of the day remains for the observance. A tithi that ends at 10:40 in the morning leaves only a few usable hours, while one running past midnight covers the whole day — the same named tithi can therefore feel very different from one day to the next.

Tithi Today for India (Delhi reference)

Today’s tithi is Krishna Chaturdasi, current till 11:28 (IST).

Times below use the Delhi reference coordinates. Panchang values depend on your exact location — pick your city for sunrise-anchored local times.

Full day details

Detailed astronomical attributes for the day
Tithi	Krishna Chaturdasi
Nakshatra	Svati
Yoga	Ayusman
Yoga ends	03:03 (+1 day)
Karana	Sakuni
Karana ends	11:28
Sunrise	06:38
Sunset	17:31
Moonrise	05:36
Moonset	16:39

Methodology and reference

All timings on this page are computed astronomically for Delhi, India — solar and lunar positions, the Lahiri (Chitrapaksha) ayanamsa and sunrise-anchored window divisions — and regression-checked against the Government of India publication Rashtriya Panchang (Positional Astronomy Centre, India Meteorological Department, Kolkata). Data verified against the Positional Astronomy Centre, IMD (Government of India) publications on every site update; the computation method is described on the about page.

What a tithi is

A tithi is the time the Moon takes to gain twelve degrees on the Sun. Tithis last between roughly 21 and 26 hours, so one can begin after sunrise on one day and end before sunrise on the next. That is why the tithi shown for a day is the one current at local sunrise, and why the same tithi can fall on a different calendar date in another city.

How the tithi index is computed

The lunar day follows from the elongation of the Moon ahead of the Sun along the ecliptic. With the sidereal longitudes of the two bodies measured at the same instant, the running tithi number is

Tithi index = floor( ( longitude of Moon − longitude of Sun ) mod 360° ÷ 12° ) + 1

Each of the 360 degrees of elongation is therefore cut into thirty 12-degree slices: index 1–15 covers Shukla Paksha (the waxing fortnight, ending at Purnima) and index 16–30 covers Krishna Paksha (the waning fortnight, ending at Amavasya). This site evaluates the formula with the Lahiri (Chitrapaksha) ayanamsa at each city’s local sunrise — the Udaya Tithi convention.

Boundary cases: kshaya and vriddhi tithi

Because a tithi averages about 23.6 hours (ranging roughly 21.5 to 26.5 hours) while sunrises recur every 24 hours, the two cycles drift against each other:

Kshaya (loss) tithi — a tithi that begins after one sunrise and ends before the next, touching no sunrise at all. A whole lunar day is skipped on paper. Smarta calendars date observances fixed to it by the day the tithi begins; Vaishnava (ISKCON) calendars shift such dates to the following day.
Vriddhi (expansion) tithi — the opposite case: a long tithi that spans two consecutive sunrises, so the same lunar day is current on two calendar days. Observances tied to its end (such as Purnima or Amavasya observances) are kept on the second of the two days.

Tables on this site mark kshaya dates explicitly; vriddhi shows up naturally as the same tithi appearing on two consecutive day rows.

Tithi for other cities

Mumbai Delhi Bangalore Pune Hyderabad Ahmedabad Chennai Kolkata Jaipur Jodhpur Indore Udaipur

Frequently asked questions

What is the difference between Udaya Tithi and the astronomical tithi?: The astronomical tithi is a continuous 12-degree slice of Moon-Sun elongation that runs its course at any clock hour. The Udaya Tithi convention — used across most North Indian panchangs and this page — dates a calendar day by whichever tithi is current at local sunrise. Some southern and Telugu traditions instead key certain observances to the tithi prevailing at other anchors such as sunset (Pradosh) or moonrise (Sankashti).
Can two tithis occur on the same calendar day?: Yes. When a long tithi spans two consecutive sunrises (a vriddhi tithi), the same lunar day is current on two calendar dates. The reverse also happens: a short tithi can begin after one sunrise and end before the next (a kshaya tithi), skipping a lunar day entirely — these dates are marked (kshaya) in this site’s tables.
Why does the tithi end time matter more than the tithi name?: Observances are kept while the tithi is current, so the end moment decides how much of the day remains for the observance. A tithi that ends at 10:40 in the morning leaves only a few usable hours, while one running past midnight covers the whole day — the same named tithi can therefore feel very different from one day to the next.