NIDARSHANA VEDH: TEST SET FOR "HOW WE CHECK OUR NUMBERS"
https://nidarshanavedh.com/accuracy/

Run date: 31 October 2026. Engine: the live website's own JavaScript (static/js/nv-transit.js and friends),
run unchanged in Node.js, reading the same NASA JPL DE440 tables the site serves (/data/ephem/v2/).
Licence: CC BY 4.0. Please credit "Nidarshana Vedh, https://nidarshanavedh.com/accuracy/".
The moments and births are chosen dates or drawn with a fixed random seed. No personal data is included.

FILES

positions-vs-nasa-horizons.csv   20 moments from 1900 to 2075 x 10 bodies (Sun to Pluto), 200 rows
  utc                    the instant, Universal Time
  tt_jd                  the same instant as a Julian day in Terrestrial Time, as sent to Horizons
  city                   label only (positions are geocentric, so the place does not change them)
  ours_tropical_deg      our apparent tropical ecliptic longitude of date, degrees
  horizons_tropical_deg  NASA JPL Horizons, quantity 31 (observer ecliptic longitude of date, apparent), degrees
  diff_arcsec            ours minus Horizons, seconds of arc
  horizons_url           a request that returns that row's Horizons value on its own (paste it into a browser)

sunrise-sunset-vs-usno.csv   7 cities x 6 dates in 2026
  ours_sunrise_local / ours_sunset_local   our times, local clock, to the second
  usno_sunrise_local / usno_sunset_local   US Naval Observatory times (published to the whole minute)
  diff_..._s                               ours minus USNO, seconds (USNO's rounding alone accounts for up to 30 s)
  usno_url                                 the USNO request used

ayanamsa-lahiri.csv   our Lahiri ayanamsa on 1 January (0h UT) of 1900, 1950, 1975, 2000, 2026, 2050, 2075
  (true value: mean ayanamsa plus nutation in longitude)

panchang-end-times-new-delhi-nov-2026.csv   every tithi, nakshatra, yoga and karana end time from the sunrise of
  1 November to the sunrise of 1 December 2026 for New Delhi, to the second (Indian Standard Time),
  and the time as the daily panchang page prints it (cut to the minute, not rounded)

lagna-100-births.csv   rising degree (sidereal, Lahiri) for 100 births from 1950 to 2010 in Indian cities (seed 20261031)

mahadasha-starts-20-births.csv   Vimshottari mahadasha start times for 20 births from 1925 to 2010 (seed 7), 10 periods
  each; period 1 is the one running at birth, so it starts before birth

CONVENTIONS

  Planets      NASA JPL DE440, apparent geocentric positions, true ecliptic and equinox of date. Daily samples
               (the Moon every 6 hours) with 4-point Lagrange interpolation. Range 1899 to 2075.
  Ayanamsa     Lahiri (Chitrapaksha): 23 deg 15' 00.658" at 21 March 1956, carried by IAU 2006 precession; the true
               value (with nutation) is used. Sidereal longitude = tropical longitude minus ayanamsa.
  Rahu, Ketu   mean lunar node (the true node is an option on the transits page).
  Sunrise      upper limb of the Sun with standard refraction (the Sun's centre 0.833 degrees below the horizon),
               sea level, no allowance for height.
  Moonrise     the Moon's centre on the horizon, seen from the place, no refraction. Almanacs that use the upper limb
               with refraction give a moonrise 4 to 9 minutes earlier; neither is wrong.
  Day rule     the tithi, nakshatra, yoga and karana in force at local sunrise belong to that day. Festivals use their
               own rule's time of day (sunrise, moonrise, pradosh, nishita).
  Dasha year   365.2425 days.
  Time zones   the IANA time zone database. It does not model Bombay or Calcutta local time before 1955; check the
               offset for births in those years.

HOW TO REPRODUCE A PLANET ROW

  Take horizons_url from any row of positions-vs-nasa-horizons.csv and open it. Horizons returns the apparent
  ecliptic longitude of date for that instant. Compare it with ours_tropical_deg.

SOURCES TO CREDIT

  Giorgini, J.D. and JPL Solar System Dynamics Group, NASA/JPL Horizons On-Line Ephemeris System,
  https://ssd.jpl.nasa.gov/horizons/, data retrieved 2026-Oct-31.
  Park, R.S., Folkner, W.M., Williams, J.G. and Boggs, D.H., "The JPL Planetary and Lunar Ephemerides DE440 and
  DE441", The Astronomical Journal 161:105 (2021).
  US Naval Observatory, Astronomical Applications Department, https://aa.usno.navy.mil/data/api
  NASA, JPL and USNO do not endorse Nidarshana Vedh.