Ganda Moola Nakshatra and Gandanta Junctions

Ganda Moola is a six-nakshatra calendar category

In the calendar convention used here, Ganda Moola names six of the twenty-seven equal nakshatras: Ashwini, Ashlesha, Magha, Jyeshtha, Mula, and Revati. They do not appear as six isolated stretches of the zodiac. They form three consecutive pairs around the joins where a water rashi gives way to a fire rashi. Ashlesha ends as Karka gives way to Simha; Jyeshtha ends as Vrischika gives way to Dhanu; Revati ends as Meena gives way to Mesha.

The current Drik Panchang Ganda Mool calendar exposes this as its own Panchang utility. Its public page lists the same six nakshatras and the same three water-to-fire pairings. That visible product pattern fills a useful gap between a general Moon-transit table and a birth chart: a reader can see the complete recurring intervals for a month without deriving them from twenty-seven separate ingress rows. This site calculates those intervals independently and states its own ayanāṃśa, time-range, and clock rules.

The geometry of each pair

Twenty-seven equal nakshatras divide 360° into sectors of 13°20′. The six selected sectors make three 26°40′ passages. Their boundaries are exact within the equal-sector model:

The Positional Astronomy Centre’s Panchang explanation defines nakshatra from the Moon’s nirayana longitude. That provides the calculation’s basic coordinate: apparent Moon longitude in a sidereal frame. A named nakshatra in this table is an equal angular sector. It is not a traced outline around the principal stars that lend the nakshatras their names.

nakshatra index = floor(wrapped sidereal Moon longitude ÷ 13°20′)

Index zero is Ashwini. Ashlesha and Magha are indexes eight and nine; Jyeshtha and Mula are seventeen and eighteen; Revati and Ashwini are twenty-six and zero. The sequence wraps cleanly through 360°. The calculator treats all six indexes as active, starts a passage when the sequence enters the set, records the internal boundary where one selected index changes to the next, and ends the passage when the sequence leaves the set.

Ganda Moola and Gandanta should stay distinguishable

The broad calendar interval and the exact water-to-fire seam are related, but they are not interchangeable. A Ganda Moola listing can cover the full span of two nakshatras around each join. Discussions of Gandanta often focus more narrowly on degrees near the join, and the width of that sensitive zone can differ by lineage or author. Calling all 26°40′ an exact Gandanta orb would hide that difference.

This calculator therefore gives three pieces of information in every row. “Begins” is entry into Ashlesha, Jyeshtha, or Revati. “Water–fire junction” is the precise modeled crossing of 120°, 240°, or 0° sidereal longitude. “Ends” is departure from Magha, Mula, or Ashwini. No additional Gandanta orb is assumed. A reader who follows a particular narrower degree rule can use the junction timestamp as a clear reference, while recognizing that a true start or end for that other rule requires its stated angular width.

How the Moon position is calculated

The browser uses Astronomy Engine 2.1.19 to calculate an apparent geocentric vector for the Moon and convert it to true ecliptic longitude of date. It then subtracts the site’s approximate Lahiri ayanāṃśa. The result is wrapped to the interval from 0° up to, but not including, 360°. Dividing by 13°20′ produces the current nakshatra index.

The ayanāṃśa matters. Moving the sidereal zero point moves every nakshatra boundary in tropical space, so a different Lahiri realization or another ayanāṃśa can shift a printed time. This page does not run Swiss Ephemeris and does not claim minute parity with every Panchang. It publishes the approximation in the result instead of presenting the clock as convention-free.

How the boundary search works

The selected local month is first converted to a half-open UTC interval: local midnight on the first day is included, and local midnight opening the next month is excluded. The search extends four days on both sides so that a passage crossing a month edge retains its real beginning and ending. That margin is longer than one complete two-nakshatra passage in the supported 2026–2027 range.

The search samples the Moon every three hours. The Moon cannot traverse a full 13°20′ nakshatra in that step, so a changed index brackets one boundary. Binary refinement then narrows the bracket until it is no more than fifteen seconds wide. The stored instant is the midpoint of that final bracket; displayed local and UTC clocks are shortened to the minute. A boundary exactly at the next month’s local midnight belongs to the following month, which prevents adjacent month exports from duplicating it.

After every boundary is found, the code pairs the three possible starts with the next departure from the selected six-index set. The internal selected-to-selected change becomes the junction. The result retains full duration and also calculates how many hours overlap the requested local month. CSV export preserves ISO UTC instants, four-decimal hour values, the fixed offset label, and month-edge flags so a rounded screen clock is not the only record.

A worked August 2026 example

With a fixed UTC−04:00 offset, the independent model begins its first August 2026 passage on August 3 at 12:30, crosses the Revati–Ashwini and Meena–Mesha junction on August 4 at 12:24, and leaves Ashwini on August 5 at 11:48. The full passage lasts about 47.3 hours.

For the same month and offset, the calculator returns four overlapping passages. The last begins on August 30 and ends on September 1, so August’s row deliberately prints an ending in the next month. Drik Panchang’s current Washington, D.C. August 2026 page prints four Ganda Mool periods and gives 12:30 on August 3 through 11:48 on August 5 for the first. It prints 18:14 on August 30 for the last beginning, while this site rounds its independent result to 18:15. That comparison is a useful fixture, not proof that every setting is identical; the competitor page applies a city time zone with daylight-saving adjustment, while this calculator takes one explicit fixed offset.

Why the clock offset changes the month list

The Moon event is geocentric, so changing UTC+05:30 to UTC−04:00 does not move a calculated boundary in absolute time. It changes the local clock and can change which side of local midnight contains the event. Near the first or last day, that can also change whether an interval overlaps the chosen local month. The UTC values remain unchanged and are the best comparison between two offset choices.

A fixed offset is deliberately narrower than a city and historical time-zone database. It does not know that Washington changes between standard and daylight time, or that past civil-time rules can differ from current ones. Enter the offset actually in force for the dates being studied. If an offset changes during the selected month, use the UTC column and convert each boundary under the location’s applicable zone rule.

Monthly transit calendar versus a birth calculation

A monthly table answers “When does the moving Moon pass through these sectors?” A birth calculation asks “Where was the Moon at this recorded instant?” If a birth time lies inside one displayed interval, the equal-sector convention classifies its Moon in one of the six named nakshatras. That is a position label, not a complete natal assessment. The result contains no houses, aspects, dasha sequence, planetary strengths, cancellation rules, or family predictions.

Birth time uncertainty matters near every boundary. A recorded time rounded to the nearest hour can straddle a nakshatra entry. The Janma Nakshatra calculator is designed for the birth question and can show date-only possibilities. The sidereal birth chart adds the other grahas. This calendar stores no birth details and does not connect to an account.

Monthly transit calendar versus a local Panchanga day

A boundary is an instant, while a Panchanga day is organized around local sunrise. A Ganda Moola passage may begin after sunrise, span the next sunrise, and end before a later one. A regional almanac can describe the civil date, the sunrise day, or both. This tool lists actual modeled entry and exit clocks. It does not convert them into a festival, rite, or muhurta ruling.

For the five limbs at a particular local sunrise, use the daily Panchanga calculator. For every sunrise in a Gregorian month, use the monthly Panchanga. The Moon transit calendar lists all twenty-seven nakshatra entries when the six-name filter is too narrow.

Frequently asked questions

Why are there usually three or four rows in a month?

The Moon circles the zodiac in about 27.3 days. It therefore reaches each of the three selected pairs roughly once per sidereal month. A Gregorian month longer than that cycle can include a fourth passage near one edge.

Does “Moola” mean only the nakshatra named Mula?

No. In the calendar label Ganda Moola, the selected set includes six nakshatras. Mula is one member. The interface spells the individual nakshatra “Mula” consistently with the site’s existing atlas while retaining “Ganda Moola” as the familiar search phrase.

Why does the junction sit near the middle of a row?

Each row contains two adjacent equal sectors. The boundary between them is exactly one sector after the beginning and one sector before the ending, although the Moon’s changing speed means the elapsed hours on the two sides need not match exactly.

Does latitude affect the result?

No latitude is used because this is a geocentric ecliptic-longitude calculation. Latitude and longitude matter for local sunrise, horizon events, and topocentric positions. Those would be different calculations.

Can the CSV be joined across months?

Yes, but a passage spanning a month edge appears in both monthly exports because it overlaps both intervals. The “begins before month” and “ends after month” columns expose that overlap. Deduplicate by the UTC beginning instant when combining files.