Is your birth time accurate enough to matter?

What this tool computes

With a recorded time, it recomputes the chart one, two, five, ten and fifteen minutes either side of the time entered, and reports the first sampled offset where a conclusion changes. With the time left blank, it checks every half hour across the whole day instead. A recorded-time answer is a tolerance within that fifteen-minute window, not an exact transition boundary; a blank-time answer shows variation at the sampled times without pretending noon was the birth time.

The part that usually goes unsaid

A missing or rounded birth time does not stop most software. It substitutes a default — very often noon — computes an ascendant from it, and prints that ascendant in the same typeface as everything else. Every finding judged from the ascendant then rests on a placeholder, and nothing on the page distinguishes it from a finding that would survive any time you gave it.

It is worth knowing where the uncertainty actually sits. Planetary positions were checked against JPL at 2000 sampled epochs. The largest Sun-through-Saturn difference was 0.44 arcseconds. A quarter-hour birth-time error can move the ascendant by several degrees; sampled positional accuracy does not verify that input or every derived chart finding.

What the result does and does not mean

The tolerance is not a judgement on whether your recorded time is correct. It cannot know that. It checks whether the selected fields change at the sampled offsets. A change between samples or outside the tested interval may be missed.

An unchanged result means the checked fields stayed the same at the sampled times. It does not prove that all report findings are independent of birth time or remove the original objection. A change means the relevant field is sensitive within the tested interval; it does not establish which recorded time is correct. Interpret either result against the uncertainty in the actual birth record.

My birth time is a family guess. Should I still run it?

If the family time could be wrong by more than fifteen minutes, leave the field blank and use the full-day sweep. Enter the guess only when you have a reason to treat it as reliable to within fifteen minutes. A narrow test around an hours-wide guess cannot establish that the rest of the day is safe.

Does a rough birth time change the guna score?

Usually not. The eight kootas are computed from the Moon, which crosses a nakshatra pada boundary roughly every six hours on average, so a quarter of an hour commonly leaves the birth star — and therefore most of the 36 points — untouched. The findings that move are the ones judged from the ascendant, which includes Mangal dosha under any tradition that counts houses from the lagna.

Is this the same as birth-time rectification?

No. Rectification is the classical practice of working backwards from dated life events to a time that fits; it is slow, done by a person, and traditions differ on how much confidence it earns. This tool does the opposite and much smaller job: it tells you whether the exercise would change anything in your case before you consider it.