Choose your Moon sign above, or enter your birth details and let the tool find it, then give the place you are in, a start date and how many months you want. This free calculator lists every Chandrashtama in that span: the time the Moon enters the 8th sign from your Moon sign, the time it leaves, how long it lasts and the dates it touches on your local calendar. If one is running now, the answer says so and when it ends; for a span wholly in the past or the future, it names the first one in that span.
How it works
Chandrashtama means the Moon (chandra) in the eighth (ashtama). Count from your Moon sign as the 1st: the 8th sign from Mesha (Aries) is Vrishchika (Scorpio), from Vrishabha (Taurus) it is Dhanu (Sagittarius), and so on round the zodiac. The Moon passes through every sign once in each round of about 27 days, so Chandrashtama comes once a round.
The tool takes the exact moments the Moon enters and leaves that sign from the NASA JPL DE440 tables used across this site, in the sidereal zodiac with the Lahiri ayanamsa, and shows them on the clock of the place you choose, daylight saving included. In our checks the Moon stayed in one sign for between about 47 and 61 hours, about two and a quarter days on average, so a Chandrashtama usually touches three calendar dates.
The rule is the Moon’s transit table: counted from the birth Moon sign, the 8th is one of the houses the table marks unfavourable for the Moon. That table is in Phaladeepika, ch. 26, and it is the one on our transits page; P.V.R. Narasimha Rao gives the same reading in Vedic Astrology: An Integrated Approach (2000), ch. 25.2, Table 54. It is also part of Chandrabala, the Moon’s strength for your sign, which our Chandrabala calculator explains.
Reading the result
Each row gives the start and end on your local clock, the length and the dates it touches. A date at the edge of a window is partly inside it: if the Moon enters at 9 pm, only the last three hours of that day are Chandrashtama. The times are exact to the minute for the Moon’s place, so use them rather than the dates alone.
Under the result, Add to my calendar saves every window in the list as a calendar file (.ics) with its exact start and end. The file holds the moments themselves, so a calendar set to another time zone still shows each window at the right time. It is made in your browser and is not sent to us.
Tradition looks at Chandrashtama when choosing a time to begin something, such as a journey, a purchase or a ceremony, along with the other checks of a muhurta. It is not a forecast that anything will go wrong, and daily life goes on as usual. If you are choosing a date, the muhurat finder and the tarabala calculator cover the other checks.
Where traditions differ
The count itself is the same everywhere; what differs is how it is printed. A printed almanac that lists Chandrashtama by date has to choose which dates to name when the Moon changes sign in the middle of a day, and the times here show exactly where it begins and ends. An almanac using another ayanamsa can put the change some minutes earlier or later. Chandrashtama is counted from the Moon sign at birth, so if you were born near a change of sign, check your Moon sign with a birth time: without one, the tool shows both possible signs when the Moon changed sign on your birth date.
What it does not do
It does not judge a whole day, which also depends on the tithi, nakshatra, weekday and the rest of the muhurta, and it does not forecast events. It works from the Moon sign only, not the birth nakshatra or its pada. Dates from 1900 to 2074 can be entered. Before 1951 the clock of a place comes from your browser’s time zone database, which can hold local mean time rather than the standard time then in use.
To find your Moon sign first, use the Moon sign calculator.
Frequently asked questions
↳ What is Chandrashtama?
The time the Moon passes through the 8th sign from the sign it was in at your birth, counting your own sign as the 1st. It comes once in each round of the Moon, about once a month.
↳ How long does Chandrashtama last?
As long as the Moon takes to cross one sign: between about 47 and 61 hours in our checks, about two and a quarter days on average. The tool gives the exact start and end.
↳ Which sign is my Chandrashtama?
Count eight signs from your Moon sign, your own sign being the first. For Mesha (Aries) it is Vrishchika (Scorpio); for Simha (Leo) it is Meena (Pisces). The tool names it for you.
↳ Should I avoid everything during Chandrashtama?
No. Tradition looks at it when choosing a time to begin something new, along with the other checks of a muhurta. It is not a forecast, and ordinary life goes on as usual.
↳ Why does my almanac give different dates?
An almanac lists dates, and the Moon usually enters the sign partway through one day and leaves partway through another, so it has to choose. It may also use another ayanamsa or another city's clock. The tool gives the exact times for your city.
↳ Do I need my birth time?
Not if you know your Moon sign: choose it from the list. Otherwise the date and place are often enough, because the Moon stays in a sign for more than two days; if it changed sign on your birth date, both signs are shown.
↳ Can I add my Chandrashtama days to my calendar?
Yes. Under the result, press Save the calendar file. It holds every window in the list with its exact start and end, so the calendar on your phone or computer shows them on its own clock. If the birth time is not known and the Moon changed sign on the birth date, there is one file for each Moon sign. The file is made in your browser and is not sent to us.