Kundli Matching by Date of Birth — What two dates alone can settle, what the missing birth time costs, and why the Moon is the reason

A birth date without a time fixes the Moon only to within a day of motion — about 13.2°. That is under half a rashi but a full nakshatra, so dates alone reach the 15 sign-derived points and almost never the 21 nakshatra ones.

kundli matching by date of birth, kundli matching, guna milan, ashtakoot, kundali milan

What two dates alone can settle, what the missing birth time costs, and why the Moon is the reason.

This is the most common real-world situation in matching: both families know the dates, nobody wrote down the times. It is also where most calculators quietly break, because a Guna Milan score needs a Moon position and a date alone does not give one.

The Moon is the fastest-moving body in the chart. It covers roughly 13.2° of the zodiac every day — which means that between midnight and midnight on your birth date, the Moon swept a 13.2° arc, and your actual birth Moon is somewhere inside it. Everything in Ashtakoot is computed from where in that arc you landed.

How much that matters depends entirely on how wide the box is. A rashi is 30° across, so a 13.2° sweep usually stays inside one sign — you get the sign right most of the time. A nakshatra is 13°20′ across, almost exactly the daily sweep, so the Moon changes nakshatra on very nearly every day of the year. That single arithmetic fact is what separates this page from the name-based route.

The 15 points two dates can reach

Four kootas read the Moon sign and nothing finer. Those four survive a missing birth time.

We verified the independence rather than assuming it. Holding two Moon signs fixed and varying the nakshatras across all 729 possible combinations, the Varna + Vashya + Graha Maitri + Bhakoot subtotal never moved: one distinct value across all 729 runs. Those four kootas genuinely do not read the nakshatra.

Note the shape of what you get. Bhakoot alone is 7 of these 15, and Bhakoot is the koota most likely to zero out — so a date-only match tends to be dominated by a single pass/fail factor rather than spread across many. That is worth knowing before you read a partial score as reassurance.

Koota	Max points	Computed from	Reachable from a date alone?
Varna	1	Moon sign → varna rank	Yes, if the sign is unambiguous
Vashya	2	Moon sign → vashya class	Yes, if the sign is unambiguous
Graha Maitri	5	Moon sign lords → friendship table	Yes, if the sign is unambiguous
Bhakoot	7	Distance between the two Moon signs	Yes, if the sign is unambiguous
Tara	3	Nakshatra distance both ways	No — nakshatra changes almost daily
Yoni	4	Nakshatra → yoni animal	No
Gana	6	Nakshatra → Deva / Manushya / Rakshasa	No
Nadi	8	Nakshatra → Adi / Madhya / Antya	No

Reachable total: 15 of 36 — and only when the Moon did not cross a sign boundary during the birth day.

Why "usually the right sign" is not the same as "the right sign"

The Moon covers 13.2° a day against a 30° sign. That is a boundary crossing on roughly 44% of days.

If the Moon travels 13.2° during your birth date and a rashi is 30° wide, the chance that a sign boundary falls somewhere inside that sweep is about 13.2 ÷ 30 — call it 44%. On those days the Moon was in one sign at breakfast and the next by evening, and a date-only calculation has to pick one. Most tools silently assume noon.

The cost of picking wrong is not small, because Bhakoot is a distance measurement between the two signs. Move one person by a single sign and the distance changes, which can flip Bhakoot between 0 and 7 in one step.

The table below is the same pair of people with one of them shifted by exactly one sign — the error a noon assumption makes on a boundary day. The sign-derived subtotal doubles.

Groom Moon	Bride Moon	Varna	Vashya	Graha Maitri	Bhakoot	Sign subtotal
Vrishabha	Kanya	1	1	5	0	7 of 15
Mithuna	Kanya	0	2	5	7	14 of 15
Vrishabha	Tula	1	1	5	7	14 of 15
Mithuna	Tula	1	2	5	0	8 of 15

One sign of drift moves the subtotal from 7 to 14, or from 14 back to 8. On a boundary day, a noon assumption is a coin flip on half the reachable points.

The nakshatra half is not degraded — it is gone

A nakshatra spans 13°20′, which is 13.33°. The Moon travels about 13.2° per day. Those two numbers are almost identical, and the consequence is stark: on very nearly every date, the Moon occupies two different nakshatras at some point during the day. A birth date narrows your nakshatra to "one of two", and which one depends entirely on the hour.

This is why we do not print a nakshatra-derived score from a date alone. It is not that the number would be imprecise; it is that there are two defensible numbers and the date contains no information to choose between them. Nadi alone is 8 points and flips entirely on that choice.

This is also the exact inverse of the name-based route. A name pins the nakshatra and cannot reach the sign; a date pins the sign and cannot reach the nakshatra. Neither is a weaker version of the other — they are complementary halves, and putting both together is simply what a full birth record does.

What to do when the time is genuinely lost

First, look harder than you expect to need to. Hospital records, birth certificates in some states, a parent's diary, and older family horoscopes cast at the time all carry it. A recovered birth time converts a 15-point partial into a full 36-point match plus Manglik, which is a larger jump than any refinement of the partial.

Second, if the time is truly unrecoverable, birth-time rectification works backwards from dated life events to narrow the window. It is not magic and it does not always converge, but it is a real method and it is honest about its confidence.

Third — and this is the part most guidance skips — a 15-point partial is still legitimate input for the sign-level questions it covers. Bhakoot and Graha Maitri are genuinely computable and genuinely meaningful within their scope. Just do not let a partial score be read as a complete one, which is what a bare percentage invites.

How far the Moon moves, and what that does to each unit

The whole of this page follows from three numbers and their ratios.

Unit	Width	Moon travel in one day	Chance of a boundary inside the day
Rashi (Moon sign)	30°	~13.2°	~44%
Nakshatra	13°20′ (13.33°)	~13.2°	~99%
Pada (quarter nakshatra)	3°20′ (3.33°)	~13.2°	Certain — about 4 padas per day

The Moon's speed varies between roughly 12° and 15° per day with its orbit, so these are averages. The nakshatra figure is close enough to certainty that we treat a date-only nakshatra as unknown.

A date-only match, computed honestly

Two birth dates, no times. Both Moon positions resolve to a sign well away from a boundary, so the sign half is safe. We compute only the four sign-derived kootas and refuse the rest.

Step	Value
Groom Moon sign	Vrishabha (lord Venus), unambiguous — Moon mid-sign all day
Bride Moon sign	Kanya (lord Mercury), unambiguous
Varna — Vrishabha rank vs Kanya rank	1 of 1
Vashya — Vrishabha (Chatushpad) × Kanya (Manav)	1 of 2
Graha Maitri — Venus × Mercury friendship	5 of 5
Bhakoot — sign distance 5/9	0 of 7, Bhakoot dosha present
Tara / Yoni / Gana / Nadi	Not computed — nakshatra unknown without a birth time

7 of the 15 date-reachable points, with Bhakoot dosha flagged. 21 points remain genuinely unknown.

Do not read 7/15 as "47%". Bhakoot dosha is the headline here and it is a pass/fail flag, not a fraction — and the 21 unknown points include Nadi, which is the single largest koota. This partial says something real about sign-level fit and nothing at all about the nakshatra layer.

Frequently asked

Can kundli matching be done with date of birth only?

Partially. Two birth dates give you the Moon signs, which determine four of the eight kootas — Varna, Vashya, Graha Maitri and Bhakoot, worth 15 of 36 points. The other four kootas are computed from the nakshatra, and because the Moon travels about 13.2° a day against a 13°20′ nakshatra, a date alone almost never pins the nakshatra down.

How accurate is kundli matching without birth time?

The 15 sign-derived points are accurate whenever the Moon did not cross a sign boundary during the birth day, which is true about 56% of the time. On the other 44% the sign itself is uncertain, and a one-sign error can swing the subtotal from 7 to 14. The 21 nakshatra-derived points are not available at any accuracy.

Why does birth time matter so much for Guna Milan?

Because the two things it unlocks are the two biggest. The nakshatra unlocks Nadi (8 points) and Gana (6), and the Lagna unlocks Manglik, which is a separate assessment from the 36 points entirely. Everything else in the system moves more slowly and survives a rough time.

What if only one person's birth time is known?

You get the sign-derived 15 points for the pair, plus a Manglik reading for the one person whose Lagna you have. You still cannot compute the nakshatra-derived kootas, because all four of those compare both nakshatras and one of them is missing.

Is 18 out of 36 still the pass mark if half the points are missing?

No, and this is a common trap. The 18-point convention refers to a complete 36-point calculation. A partial score cannot be compared against it — 15 of 15 and 15 of 36 are very different situations that produce the same number.

What this page can NOT tell you

• A date without a time cannot compute Tara, Yoni, Gana or Nadi — 21 of the 36 points — because the Moon changes nakshatra on very nearly every day.
• It cannot assess Manglik status. Manglik is measured from the Lagna, which advances a full sign roughly every two hours and is undefined without a birth time.
• On roughly 44% of dates the Moon crosses a sign boundary during the day, so even the sign-derived 15 points can be wrong if a tool silently assumes noon. We flag the ambiguity instead of picking for you.
• A partial score is not a percentage of 36. Presenting 7 of 15 as "19%" or "47%" both mislead — the missing points are unknown, not zero.
• No koota total, partial or complete, predicts whether a marriage will last. Ashtakoot is a classical screening heuristic, not an outcome model.

The 15/21 split and the nakshatra-independence check across all 729 nakshatra combinations were produced by running the engine directly. The boundary probabilities are the ratio of the Moon's mean daily motion to each unit's width and are stated as approximations because the Moon's speed varies with its orbit.

How AskSoma computes and what we refuse to claim · Engine: Swiss Ephemeris via @asksoma/compatibility-core (calculateGunaMilan), Lahiri sidereal Moon longitude · Ayanamsa: Lahiri (Chitrapaksha) · Content reviewed 2026-08-07