Sunrise, brahma muhurta and the lunar day — computed for your city

What this calendar is

Every figure on these pages is calculated when you load the page, from published astronomical algorithms and the city's coordinates. Nothing is copied from another site and nothing is stored: sunrise, sunset, day length, the brahma muhurta window, the lunar day, the Moon's illuminated fraction and the nakshatra are all derived from the Sun's and Moon's computed positions for that date and place.

That matters because practice timing is one of the few areas of yoga where a website can give you something genuinely factual instead of another paraphrase. Where the tradition is specific, we quote it. Where it is vague or varies between schools, we say so rather than inventing precision.

The three things the calendar tracks

Solar timing. Sunrise, solar noon and sunset, computed for the horizon at sea level with the usual allowance for atmospheric refraction and the Sun's apparent upper limb. From sunrise we derive the brahma muhurta window — roughly 96 to 48 minutes before sunrise — and the day's length. The point of anchoring to sunrise rather than the clock is that the clock is an administrative convention: in Seattle the gap between midsummer and midwinter sunrise is nearly four hours, so "6 a.m. practice" means something completely different in January than in June.

Lunar timing. The tithi, or lunar day, is the time the Moon takes to gain twelve degrees of elongation on the Sun. Thirty tithis make a lunar month, fifteen in the waxing fortnight (shukla paksha) and fifteen in the waning (krishna paksha). The eleventh of each fortnight is ekadashi; the fifteenth of the waxing fortnight is purnima, the full moon; the thirtieth is amavasya, the new moon. These are the days most Indian observances hang on, and they cannot be read off a Western calendar.

Nakshatra. The Moon's position against the twenty-seven sidereal lunar mansions. This is astronomical bookkeeping in Jyotisha, computed here with a linear Lahiri-style ayanamsa approximation. It is included because people look for it, not because the yoga texts make practice depend on it.

What the texts say about when to practise

The classical corpus is more interested in how consistently you practise than in hitting an exact minute. Patanjali's Yoga Sutras (1.14) make the only timing claim that really matters: practice becomes firmly grounded when pursued for a long time, without interruption, and with earnest attention. There is no hour named.

The hatha texts add conditions rather than clock times. The Hatha Yoga Pradipika cautions against beginning in the extremes of winter, summer or the rains, advises practice on an empty stomach, and describes dawn and dusk as the times for pranayama. The Gheranda Samhita gives comparable seasonal and dietary cautions. Later ritual and ayurvedic literature is where the detailed dinacharya — the daily routine built around brahma muhurta — is set out most fully, and where the strongest claims for pre-dawn practice come from.

So the honest summary is this: pre-dawn practice is a well-attested traditional recommendation with a long pedigree in Indian daily-routine literature, and it has a practical logic anyone can verify — the world is quiet, the stomach is empty, and nothing has yet claimed your attention. The specific metaphysical claims made for that window belong to tradition, and we present them as tradition.

How to use it

Open your city, look at today's row, and work backwards from sunrise rather than forwards from your alarm. If the brahma muhurta window is unreachable this month — and in a northern city in June it may begin before three in the morning — the tradition's own principle applies: consistency outranks the ideal hour. Practise at a time you can actually keep, note which lunar day it is if your tradition asks you to, and let the window move with the season.

Accuracy, stated plainly

Sunrise and sunset should be within a minute or two of an observatory table for a sea-level horizon; local hills, buildings and altitude will shift what you actually see, sometimes by several minutes. Tithi and nakshatra come from truncated lunar series accurate to roughly a tenth of a degree, which is ample for identifying the lunar day but can disagree with a full ephemeris right at a boundary. None of this is offered for ritual or muhurta determination — for that, use a panchanga from your own tradition.