What is Chandrashtama?

The period when the transiting Moon sits in the 8th sign from the sign your Moon occupied at birth. It comes around once a lunar month and lasts about fifty hours. Because it is keyed to your own natal Moon, it falls on different days for different people.

How do I calculate my Chandrashtama sign?

Count eight signs from your natal Moon sign, counting that sign as the first. A Scorpio Moon gives Gemini. The sign never changes — only the dates the Moon reaches it. Enter your birth details above and the tool does both parts.

Is Chandrashtama a bad day?

The tradition treats it as a poor time to begin things rather than a day on which bad things happen, and we would rather state that plainly than dress it up. Signing, launching, starting treatment or travelling for something that matters are the classical cautions. Living your ordinary day is not on the list.

How often does Chandrashtama occur?

Once per lunar month — roughly every 27 days — for about fifty hours. The exact length varies by an hour or more between occurrences because the Moon's speed is not constant, which is why the windows here are scanned from the ephemeris rather than assumed.

Why do the times differ from another site's?

Usually timezone, sometimes ayanamsa. These windows are Moon transits, so the instants are identical worldwide — but a site showing them in UTC, or in your browser's zone, or in a fixed zone of its own will print different clock times for the same moment. This page shows them in the timezone of the birth place you entered, and says so.

Free tool

Chandrashtama Calculator

The recurring windows when the transiting Moon sits 8th from your natal Moon — dated, in your own timezone, and framed as the tradition frames them.

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What Chandrashtama is, and how often it happens

Chandrashtama is the period when the transiting Moon occupies the 8th sign counted from the sign your Moon was in at birth. Because the Moon circles the zodiac in about 27 days and spends roughly two and a quarter days per sign, it happens once a lunar month and lasts about fifty hours.

It is personal in a way that most 'avoid' periods are not. Rahu Kaal is the same for everyone in a city on a given day; your Chandrashtama depends on your own natal Moon, so two people in the same room can be having very different days by this reckoning.

The one thing you need to know it is your natal Moon sign. Everything else — which sign is 8th from it, and when the Moon is next there — follows from that.

Find your natal Moon sign first →

How to read your result

The headline is your Chandrashtama sign — the 8th from your natal Moon. It never changes; only the dates do.

Below it are the upcoming windows, each with a start and end date and time. They are shown in the timezone of the birth place you entered rather than in UTC or in your browser's zone, because that is the clock most people are actually planning against.

If a window is running as you read the page, it is called out at the top. Windows are about fifty hours, so they routinely cross two midnights — which is why every time here carries its date rather than just a clock reading.

A worked example

Take the chart used across these pages: the natal Moon is in Scorpio. Counting eight signs from Scorpio — Scorpio itself is first — lands on Gemini. So Gemini is that chart's Chandrashtama sign, permanently.

The Moon reaches Gemini roughly every 27 days. One such window opens on 5 September 2026 at 10:18 AM India time and closes on the 7th at 12:38 PM: about fifty hours spanning three calendar dates.

Note what that means for a naive display. Shown as clock times alone — '10:18 AM to 12:38 PM' — it reads as one afternoon. Shown in UTC it opens at 04:48, and for a reader far enough west it would open on the previous day entirely. The dates are not decoration.

Method

Your natal Moon comes from a Swiss Ephemeris chart computation, sidereal with the Lahiri ayanamsa — the same chart every other tool here reads. The Chandrashtama sign is the 8th from it, counted inclusively in the usual way.

The windows are the transiting Moon's actual ingress and egress for that sign, scanned from the ephemeris rather than approximated at 2.25 days per sign. That matters because the Moon's speed varies: windows in the list differ from each other by an hour or more.

Because they are Moon transits, the instants are the same everywhere on Earth. Only the clock you read them on differs, which is why the page states which timezone it is using.

What this does not tell you

It does not predict that anything bad will happen, and the classical reading does not either. Chandrashtama is advice about BEGINNING things — signing, launching, travelling for something that matters, starting a course of treatment. Ordinary life is not suspended for fifty hours a month.

It says nothing about anyone else's day. This is keyed to your natal Moon alone.

It is one factor among many. A practitioner weighing a date would look at the dasha, the transits and the muhurta alongside this, and any of those can outweigh it.

And it depends on your birth details being right — specifically the date. The Moon changes sign roughly every two and a quarter days, so a wrong date can shift the natal Moon and hand you the wrong Chandrashtama sign entirely.

Sade Sati — the long Saturn cycle instead →

Frequently asked

What is Chandrashtama?: The period when the transiting Moon sits in the 8th sign from the sign your Moon occupied at birth. It comes around once a lunar month and lasts about fifty hours. Because it is keyed to your own natal Moon, it falls on different days for different people.
How do I calculate my Chandrashtama sign?: Count eight signs from your natal Moon sign, counting that sign as the first. A Scorpio Moon gives Gemini. The sign never changes — only the dates the Moon reaches it. Enter your birth details above and the tool does both parts.
Is Chandrashtama a bad day?: The tradition treats it as a poor time to begin things rather than a day on which bad things happen, and we would rather state that plainly than dress it up. Signing, launching, starting treatment or travelling for something that matters are the classical cautions. Living your ordinary day is not on the list.
How often does Chandrashtama occur?: Once per lunar month — roughly every 27 days — for about fifty hours. The exact length varies by an hour or more between occurrences because the Moon's speed is not constant, which is why the windows here are scanned from the ephemeris rather than assumed.
Why do the times differ from another site's?: Usually timezone, sometimes ayanamsa. These windows are Moon transits, so the instants are identical worldwide — but a site showing them in UTC, or in your browser's zone, or in a fixed zone of its own will print different clock times for the same moment. This page shows them in the timezone of the birth place you entered, and says so.