Natonnata Bala Made Simple: A Planet's Day–Night Strength (and Why Two Programs Disagree)

• 18/7/2026
• 5-minute read

Where Natonnata Bala fits in Shadbala

In classical Vedic astrology, a planet is not simply “good” or “bad” — what matters is how strong it is to deliver its results. The traditional yardstick is Shadbala (“six-fold strength”): six sources of power that are each measured in points and added up.

One of those six is Kaala Bala — temporal strength, i.e. strength that depends on the time of birth. And inside Kaala Bala sits a small but important piece called Natonnata Bala (also called Divaratri Bala, the “day–night strength”).

This post explains Natonnata Bala in plain language, works it out on a real example, and then looks at something curious: two popular astrology programs — Vinayak Hora and Jagannatha Hora — report different values for it. We’ll see, with the actual arithmetic, which one follows the classical textbook.

The idea behind Natonnata Bala

Some planets are considered day-strong (diurnal). Some are night-strong (nocturnal). One is neutral.

The measure runs from 0 to 60 points (Vedic texts call these units shashtiamsas, literally “sixtieths”). A day-strong planet earns the full 60 if the birth is exactly at noon, and less as birth moves away from noon toward midnight. The night-strong planets are the mirror image — full at midnight. The two groups always add up to 60, like a see-saw.

The whole calculation, then, boils down to one question:

How far is the moment of birth from local noon?

Our example chart

Let’s take an example birth (name changed for privacy):

• Name: Rakesh Verma (illustrative)
• Born: 24 October 1972, 2:14 PM
• Place: Delhi

For that day and place, the Sun rose at 6:31 AM and set at 5:38 PM. So:

• Length of day (sunrise to sunset): about 11 hours 7 minutes.
• Local noon (the mid-point of the day, when the Sun is highest): about 12:05 PM.
• Birth was at 2:14 PM — that is roughly 2 hours 9 minutes after noon.

So the birth is a little after midday. The Sun, Jupiter and Venus (day-strong) should therefore be strong but not at their maximum — a value comfortably above the mid-mark of 30, but below the full 60.

Hold that intuition — “a bit above the middle, clearly not near 60” — because it’s the whole point of what follows.

The textbook calculation (B.V. Raman’s method)

The most widely followed modern reference for Shadbala is B.V. Raman’s Graha and Bhava Balas. His method for the day-strong planets is beautifully simple:

1. Take the birth time counted from midnight, in hours: 2:14 PM = 14.23 hours.
2. Multiply by 15 (because the sky turns 15° every hour): 14.23 × 15 = 213.5°. (When this crosses 180°, you fold it back: 360 − 213.5 = 146.5°.)
3. Divide by 3 to turn degrees into points: 146.5 ÷ 3 ≈ 48.8 points.

So by the textbook, the day-strong planets (Sun, Jupiter, Venus) get about 48–49 points, and the night-strong planets get the remainder, 60 − 48.8 ≈ 11 points. This matches our intuition exactly: a bit above the middle, well short of 60.

What the two programs report

Now here is the interesting part. Both programs agree on the astronomy — the sunrise, sunset, and day length above are the values both produce, matching to within a second or two. So any difference is not about the sky; it’s about the formula.

Two things jump out:

• Vinayak Hora (48.4) sits right next to the textbook value (48.8). It is, for practical purposes, the classical answer. (The tiny gap is because Vinayak Hora refines the method slightly — it scales by the actual length of that day, 11h 07m, instead of a flat 12-hour assumption. If anything, that’s a touch more faithful to the real sky.)
• Jagannatha Hora (53.5) stands about 5 points away from both — and above them.

That 53.5 is worth examining, because it doesn’t match the textbook. For Raman’s formula to produce 53.5, the birth would have had to occur near 1:18 PM, not 2:14 PM — as if the clock were wound back by nearly an hour. The usual technical corrections (for the city’s longitude and the “equation of time”) together come to only about half that, and pull in the opposite direction. In other words, the 53.5 figure does not follow from the standard calculation applied to this birth.

So which is right?

For this component, the answer is clear from the numbers:

Vinayak Hora’s Natonnata Bala agrees with B.V. Raman’s published formula and with the Sun’s actual position in the sky. Jagannatha Hora’s value does not.

This isn’t a criticism of Jagannatha Hora as a whole — it is fine, respected software with a huge feature set. But on this specific sub-calculation, if you sit down with Raman’s textbook and a calculator, the value you get is the one Vinayak Hora shows.

It’s a small number in a big table. But Shadbala is built by adding up many such small numbers, and a five-point slip in one of them quietly shifts the final strength of three planets in every chart. Getting the little things right is exactly what a careful astrologer — and careful software — should do.

The takeaway for a chart reader

• Natonnata Bala simply measures how close the birth was to noon (for day-strong planets) or midnight (for night-strong planets).
• The classical rule is easy: birth-from-midnight in degrees, folded at 180, divided by 3.
• On our example, the textbook and Vinayak Hora both land near 48–49 for the Sun; another popular program reports 53.5, which the standard formula does not reproduce.

When a program’s numbers can be traced, step by step, back to the classical texts, you can trust the chart it draws. That traceability is the quiet promise behind Vinayak Hora.

Technical note: the values above were verified by computing B.V. Raman’s Method B directly (checked against his own worked example) and by reading the exact sunrise, sunset and intermediate figures used inside each program. The two programs’ astronomical inputs were identical; only the Natonnata formula differed.