Moon sign calculator: your rashi, and how sure it is

Your Moon sign

Your result gives the sign, then the clock times the Moon entered and left that sign around your birth, and what three other systems of reckoning would call the same Moon. The box under the form is the Moon right now in Delhi, a live check that the engine is answering; it is not your result.

On 21 October 2026 we read the rashi calculator pages of Drik Panchang, AstroSage, ClickAstro and Shubh Panchang. All four say the birth time matters; none of the four pages says how far your own time could be off before the sign changes. We read the pages, not every result each one can return.

What a rashi is, in one paragraph

The zodiac is a circle of 360 degrees cut into twelve signs of 30 degrees each, from Mesha (Aries) at 0 to Meena (Pisces) at 330. Your rashi, or janma rashi, is the sign holding the Moon at your birth, measured against the stars rather than the seasons. Drik Panchang's calculator puts it the same way: "Moonsign is the name of the zodiac in which the Moon was located at the time of the birth" (Drik Panchang, rashi calculator). Nakshatras cut the same circle into 27; the nakshatra guide shows how the two divisions overlap, and the nakshatra finder gives the nakshatra and pada of the same birth Moon.

Why the time matters, measured

The Moon moves quickly. Over 1950 to 2025 our engine's settings have it moving between 11.76 and 15.39 degrees a day, and staying in one sign between 46.9 and 61.1 hours, 54.6 on average. That average agrees with NASA's Moon fact sheet, which gives the Moon's revolution period as 27.3217 days; a twelfth of that is 54.64 hours.

A stay of two and a quarter days means a sign boundary lands inside some days and not others. We took every day from 1 January 1950 to 31 December 2025, midnight to midnight on Indian Standard Time, and asked Swiss Ephemeris 2.10.03 (DE441 files, Lahiri) for the sidereal Moon at both ends: the sign differed on 12,192 of 27,759 days, or 43.9%. On those days two people born on the same date can have different rashis. On the rest the date alone settles it. NASA's period gives a rough check on that count, not a confirmation of it: if every stay were the average 54.64 hours, a 24-hour day would hold a boundary 24 ÷ 54.64 = 43.9% of the time, which is where our count lands.

So the useful question is not "is my birth time exact" but "how wrong could it be before the answer changes". The tool answers it from your own birth: if the Moon had entered its sign 40 hours before you were born and left 14 hours after, a birth certificate rounded to the half hour changes nothing. If it left 20 minutes after, the rounding matters, and the tool says so.

If another calculator gives a different sign

Three of the reasons are about how the zodiac is measured, and the tool checks each one for your Moon.

The three widths were measured with Swiss Ephemeris 2.10.03 on 1 January of 1900, 1950, 1980, 2000, 2026 and 2050; the Raman and KP gaps were identical in all six years, and the methodology page states the same two gaps rounded. Drik Panchang's calculator offers Lahiri, Raman, Krishnamurti or no ayanamsha as a setting (rashi calculator, advanced options), so two people using the same site can get different answers for the same birth.

A fourth reason is the clock. Our engine turns your birth time into an instant with the IANA time zone database, read through Python's zoneinfo, and every Indian city in the list uses its Asia/Kolkata record: +05:30 from 1906, but +06:30 from October 1941 to May 1942 and again from September 1942 to October 1945, +05:21:10 (Madras railway time) from 1870 to 1905, and Calcutta's local mean time before that: +05:53:28 until 28 June 1854, then +05:53:20. A calculator that applies today's +05:30 to a 1943 birth is an hour out. From 1870 that record follows railway time, and it is all the engine knows. It does not model Bombay Time, 4 hours 51 minutes ahead of Greenwich, which Bombay kept until 1955, nor the local time Calcutta kept after 1870, which the database's own notes say varied between the railway station and government offices; the same notes call their only source for the war-time offsets dubious. If you were born in Mumbai or Kolkata before 1955, or anywhere in India before 1906, ask which clock the time was written on before trusting a result near a boundary. The methodology page sets out the same limit.

What the town does and does not change

Nothing about the Moon's position, for a given moment. Our positions are geocentric, seen from the Earth's centre (methodology, calculation flags), so for 08:30 IST on 15 May 1990 the engine returns the same Moon, 268.82°, for Delhi, Kolkata and Thiruvananthapuram. The place matters only because it decides which clock your birth time was written on. That is why the tool offers nineteen cities rather than a search box: pick one that keeps the same clock as your birth place. The ascendant is different; it does depend on the exact place, and this tool does not compute it.

How this tool works out the times

The tool calls the engine behind the charts on this site, configured as Swiss Ephemeris on JPL DE441 files, sidereal, Lahiri ayanamsha (methodology, settings at a glance). That is the configuration, not a check made on each request: the service does not yet refuse an answer that has silently fallen back, when the data files are missing, to the library's built-in Moshier ephemeris, so this page cannot show which one answered yours. The methodology measured the two at most 2.73 arcseconds apart for the Moon, which moves an entry or exit time by 4 to 6 seconds.

The tool asks for the Moon at your birth time, then, for each of the two sign boundaries, asks again at moments closer and closer to it until the Moon sits within 0.002° of the boundary, 11 to 15 seconds of its motion. If eight tries do not get there, it gives up rather than guess. There is no formula for the Moon in this page's code and no estimate if the engine does not answer; the tool then says so and shows nothing.

For a date with no time, it asks for the Moon at 00:00:00 and at 23:59:59. In the measurement above the Moon moved forward against the stars on every day, by 11.76 degrees at the least, so the tool also checks that it covered less than 30 degrees between those two times; if so, the same sign at both ends means the same sign all day, and a day that failed the check would be refused rather than answered. No day is expected to fail it: the fastest the Moon moves is about half that, 15.39 degrees a day at most in the range above. The one gap is the day's final second, which is not asked about.

What a Moon sign is not

A rashi is a convention for reading a chart, and this page computes it; it does not tell you who you are or what will happen to you. Whatever is read from it afterwards is interpretation layered on top of a position. Nothing here should decide something that matters medically, legally or financially.