How the Chandrashtama calculator works
Chandrashtama, also written Chandrashtamam or Chandra Ashtama, is the time the Moon spends in the 8th rasi counted from your Janma Rasi (your Moon sign), with your own rasi counted as the first. The Moon passes through all 12 rasis in about 27.3 days, so it reaches your 8th rasi roughly once a month and stays there for a little over two days.
When you tap your rasi, the calculator looks up each time the Moon enters and leaves that 8th rasi and shows the next one first. The times come from the same published transit tables used across this site, computed with the Lahiri (Chitrapaksha) ayanamsa that Tamil panchangams follow. Your rasi page, the yearly calendar and this calculator therefore always show the same minute.
Chandrashtama for each Rasi
The 8th rasi never changes for a given Janma Rasi, so the whole rule fits in one table. Find your rasi in the first column: your Chandrashtama runs whenever the Moon is in the rasi beside it.
How long does Chandrashtama last?
Not exactly 48 hours. Across the 320 windows published for 2026 and 2027, the shortest lasts 47 hours and the longest 62 hours. The average is about 54.7 hours, a little over two and a quarter days.
The length changes because the Moon's speed changes. Near perigee, its closest point to Earth, it moves faster and crosses a rasi sooner; near apogee it slows down. That is why the calculator gives every window its own start, end and length instead of a fixed two-day block.
Exact times vs calendar days
A window that begins on a Tuesday evening and ends on a Friday morning touches four calendar dates, even though it lasts less than three days. Printed calendars often mark whole days only, which makes Chandrashtama look longer than it is.
The calculator shows both: the exact start and end times, and the calendar dates the window touches in the timezone you choose. Plan important work around the hours, and treat the dates as a quick reminder.
Chandrashtama outside India
The Moon enters a rasi at the same instant for everyone on Earth; only the clock reading changes. A window that starts at 11:30 pm IST starts at 2:00 am the next day in Singapore and Malaysia, and at 6:00 pm the same day in London (7:00 pm in summer).
Choose your timezone above the list of windows and every time and date changes with it. UK and US times follow daylight saving automatically, and the site remembers your choice on every page.
What to avoid and what to do
Tradition treats Chandrashtama as a time to go gently, not a time of bad luck. Families usually avoid fixing new beginnings in this window: a wedding muhurtham, a griha pravesam, signing a major agreement, or starting a business or a long journey. Everyday work carries on as normal.
Many people keep difficult conversations short, rest well and set aside time for prayer. Chanting the Chandra mantra and visiting a Shiva temple on a Monday are common practices. These are traditional beliefs, not predictions.
Frequently asked questions
What is a Chandrashtama calculator?
A tool that finds when the Moon will be in the 8th rasi from your Janma Rasi. Pick your rasi and it lists the start and end time of each window, so you know which hours to keep free of major new beginnings.
How is Chandrashtama calculated?
Count eight rasis from your Janma Rasi, counting your own as the first. Chandrashtama is the whole time the Moon spends in that rasi. For Mesha the 8th rasi is Vrichigam; for Kadagam it is Kumbam.
How long does Chandrashtama last?
Between 47 and 62 hours in 2026 and 2027, about 54.7 hours on average. It is never a fixed 48 hours.
How often does Chandrashtama come?
About once every 27 days. Each rasi has 13 or 14 windows starting in a calendar year.
Do I need my birth time?
Not if you already know your Janma Rasi: one tap is enough. If you don't, your rasi is where the Moon was when you were born. On a day the Moon changed rasi you need the birth time to be sure, and our guide explains how to find it.
Is Chandrashtama the same for everyone?
No. It depends on your Janma Rasi. At any moment the Moon is in one rasi, so only one Janma Rasi is in Chandrashtama at a time. The Chandrashtama today page shows which.
Why are the times different in Singapore or the US?
The Moon enters a rasi at the same moment everywhere, but clocks differ. The calculator converts that moment to the timezone you choose, so a window's date can move by a day.
Is this calculator accurate?
The times come from our published transit tables, computed from the Moon's actual position with the Lahiri ayanamsa and checked against published panchang times, to the minute. Panchangams that use another ayanamsa can differ by a few minutes.