How we compute the panchangam
Last updated 22 August 2026
Every number on this site is computed, not copied. This page sets out exactly how, so that when our timings differ from the panchangam on your wall you can see precisely where the difference comes from — and decide for yourself which to follow. We would rather be transparent and occasionally disagree with you than be vague and always seem right.
At a glance
- Method
- Astronomical (true positions), not tabular
- Ayanamsa
- Lahiri / Chitrapaksha
- Sunrise
- Upper limb, refraction included (90°50′)
- Day begins
- At sunrise, in the selected city
- Month convention
- Amanta, Telugu masa names
- Kalams
- Eighths of the daylight period, by weekday
- Rebuilt
- Daily, 04:00 IST
- Predictions
- None — panchangam only
Astronomical, not tabular
There are two traditions of panchangam computation. The vakya tradition uses tables and mean motions handed down in verse — elegant, portable, and by now several degrees adrift from the sky. The astronomical tradition computes where the sun and moon actually are at a given instant. We use the astronomical method throughout. Positions come from established ephemeris series — the same Meeus/VSOP-derived formulae that observatories use for planning — evaluated for the exact moment being asked about, not interpolated from a daily table.
Ayanamsa
Indian astronomy reckons positions against the fixed stars (nirayana), while modern ephemerides give them against the equinox (sayana). The difference between the two is the ayanamsa, and it grows by roughly fifty arc-seconds a year. We use the Lahiri (Chitrapaksha) ayanamsa, the value adopted by the Indian Calendric Reform Committee in 1955 and used by the Rashtriya Panchang and by the overwhelming majority of published Indian panchangams. If your panchangam uses Raman or Krishnamurti ayanamsa, expect small differences in the moment a nakshatra changes — usually minutes, occasionally enough to move a boundary across sunrise.
The five limbs
Tithi is the elongation of the moon from the sun divided into thirty parts of twelve degrees each. Nakshatra is the moon's sidereal longitude divided into twenty-seven parts. Yoga is the sum of the sun's and moon's longitudes divided into twenty-seven parts. Karana is half a tithi. Vaara is the weekday, reckoned from sunrise. We compute each of these directly from the positions, and we find the exact instant each one ends by root-finding on the underlying angle rather than by linear interpolation — which is why our end times are given to the minute rather than the quarter-hour.
Which tithi belongs to which day
A tithi rarely fills a calendar day. The convention we follow, and the one nearly every Indian panchangam follows, is that the day is named for the tithi running at sunrise. That is why a tithi shown as ending at 09:14 is still 'today's tithi' — it was the one in force when the day began. Where a vratam has its own rule (Ekadashi and its parana, for instance, or a festival tied to a particular time of day) we apply that rule instead and say so on the page.
Sunrise, and why it decides so much
Sunrise here means the moment the upper limb of the sun's disc appears on a level horizon, including the standard allowance for atmospheric refraction — a zenith distance of 90°50′. This is the convention used by published panchangams and by national almanacs. It matters far more than it sounds: sunrise starts the panchangam day, anchors the tithi rule above, and is one end of the interval from which rahu kalam, yamagandam, gulika kalam and abhijit muhurta are all derived. We compute it iteratively, re-evaluating the sun's declination at the estimated moment of the event rather than at noon, which keeps it accurate to within a few seconds.
Why your city changes everything
Sunrise in Hyderabad and sunrise in Dubai are about forty minutes apart on the same date; between Kolkata and Ahmedabad the gap is nearly an hour. Since the kalams are eighths of the daylight period, they move with sunrise. Every page on this site is computed for a specific latitude, longitude and time zone. We detect your time zone when the page loads and use the nearest city we cover; you can set it exactly from the selector in the header, and the choice is saved on your device. For cities that observe daylight saving — the ones our overseas readers live in — we resolve the offset for the particular date rather than assuming a fixed one.
Amanta and purnimanta
The lunar month is reckoned from new moon to new moon in the south and west (amanta) and from full moon to full moon in the north (purnimanta). The two conventions name the same month differently for a fortnight of every month, which is the single most common reason two panchangams appear to disagree. Our default is amanta with Telugu masa names, which is what our primary readership uses. Where a festival is commonly dated by the other convention we note it on the festival's page.
Festival dates
Festival dates are the one place we do not simply compute and publish. A festival is a tithi rule plus a regional custom, and customs differ legitimately — Vinayaka Chaviti, Deepavali and Sankranti are all observed on different days by different communities in the same year. Our festival dates come from validated data reviewed against published panchangams, not from a formula alone, and where two dates are in common use we say so rather than quietly picking one.
What we deliberately do not publish
No kundali, no horoscope matching, no rashifal, no predictions of any kind. A panchangam describes the sky; it does not forecast your life. Keeping that line clear is a positioning decision as much as an editorial one, and it is why you will not find a 'lucky colour' anywhere on this site.
Corrections
We publish a corrections policy because a site that computes thousands of numbers a day will eventually get one wrong. If you find an error — a timing, a date, a transliteration, a translation — write to info@redlapdigital.com with the page and what you believe the correct value is. We check every report against our sources, correct verified errors in the next daily build, and will tell you what we found either way. Systematic errors get a note on this page.
How often this is rebuilt
The site is regenerated every day at 04:00 IST, so 'today' is always today. Pages for past and future dates are generated across a rolling window; dates outside it are still reachable and still correct, they are simply not offered to search engines for indexing.