☾ Chandrashtama Today: Whose Moon Is in the 8th?

Give your birth nakshatra, your Moon sign or your birth date, and where you are. Each row is one Vedic day, sunrise to sunrise, with the Moon's nakshatra and sign, the minute it changes, and the sum behind each answer.

Chandrashtama (chandra, Moon; ashtama, eighth) is the time the Moon is in the 8th sign counted from your birth Moon sign. The Moon passes through a sign in about two and a quarter days, so each Moon sign has one such stretch every lunar month, about every 27 days, and it lasts around two and a quarter days. The eighth is the house of endings and the unknown in Jyotish, and almanacs advise postponing new beginnings, long journeys, signatures and important purchases while the Moon is there, and treat it as a quieter time for routine work and rest.

It is a special case of the unfavourable Chandrabalam positions, and the one most often published as its own daily line. The tradition varies in what it forgives: some teachers soften it for certain placements of the Moon or when the day's other factors are strong. Umbriel applies no exceptions and says so.

The signs are the sidereal ones. The pairing is always seven signs back, since the 8th from a sign is seven signs forward.

Suppose your birth Moon is in Cancer, sign 4. Count forward to the sign where the sum reaches eight: Aquarius is sign 11, and 11 − 4 + 1 = 8. So whenever the Moon is in Aquarius, Cancer Moons have Chandrashtama. When it moves on to Pisces, sign 12, the count is 9, and it is over.

Chandrashtama counts from the sidereal Moon sign, which differs from the Western Moon sign by the ayanamsa, about 24 degrees. About four times in five your sidereal Moon is in the sign before your tropical one. If you read the table above with a Western sign you will usually be a sign out, one stretch of the month early or late. Choose "I know my birth date" below and Umbriel finds the right sign.

The Moon changes sign roughly every two and a quarter days, so on about four birth dates in nine it changed during the day. Umbriel then lists the signs it passed through with the times, and any day on which only one of the possibilities has Chandrashtama is tagged with the sign it applies to, rather than asserted.

The Moon comes from the same engine that casts every chart on Umbriel, in the sidereal zodiac with the Lahiri ayanamsa. The calendar finds each moment the Moon crosses a nakshatra boundary (every 13°20′) or a sign boundary (every 30°) by stepping through the month two hours at a time and then halving the interval until the crossing is pinned to a fraction of a second. Sunrise is the Sun's upper edge at the horizon for the place you choose, the Vedic day's own starting line, so each day runs from one sunrise to the next. The classification is then pure counting, and the sum is printed under every answer. Nothing is sent anywhere: the page works in your browser, and the calculation engine (about 780 KB) is only fetched when you first touch the form.

The "right now" strip uses a small table of Moon sign changes (about 4 KB, covering October 2026 to the end of 2027, to the minute) so that it costs nothing to load. The 30-day calendar below it works out the Moon itself and covers any date.

Checked, not assumed. The engine's Moon was compared with NASA JPL Horizons (apparent longitude of date, the geocentre) at 80 instants spread from 1950 to 2161. For the 66 of them up to the end of 2027 the largest difference was 0.17 arcminute (0.07 on average), about twenty seconds of the Moon's travel; the engine drifts to a few arcminutes by the 2100s, so only dates in the next few decades are this exact. Against a published online panchang (Drik Panchang) on five days in five places (New Delhi, Mumbai, Chennai, Kolkata and New York, between October 2026 and March 2027) every nakshatra and Moon-sign change time agreed to within one minute, and our sunrise came 1 to 1.5 minutes earlier than theirs. Not checked: the classical verse for each convention below (see the questions), birth times from before 1970 (the zone rules come from your browser, and old daylight-saving rules are the likeliest thing to be wrong), and anything beyond 30 days ahead, which the calendar does not offer.

Chandrashtama is a tradition's caution, not a prediction. Many people notice nothing, and nothing here should be read as saying a day will go badly.