பஞ்சாங்கக் கணக்கீட்டு முறை
Panchangam calculation methodology
கடைசி புதுப்பிப்பு: 2026-09-08
இது திருக்கணித முறை. வாக்கிய பஞ்சாங்கத்துடன் தேதிகளும் நேரங்களும் மாறலாம். தனிப்பட்ட முகூர்த்தத்தைத் தேர்ந்தெடுக்க குடும்ப மரபையும் ஆலோசனையையும் பயன்படுத்துங்கள்.
வானியல் தரவு
Skyfield 1.53 and the bundled JPL DE421 ephemeris calculate apparent geocentric solar and lunar ecliptic longitudes. Supported dates are 1901–2051. Calculations use no language model and make no runtime ephemeris downloads.
அயனாம்சம்
The sidereal origin is the Indian Calendar Reform Committee Lahiri anchor of 23°15′ at Julian day 2435553.5, transported through Skyfield’s precession and nutation frame. It is labelled ICRC-anchored Lahiri, rather than claiming identical implementation to every Lahiri calendar. Calculation version: panchangam-skyfield-icrc-v1.
ஐந்து அங்கங்கள்
Tithi divides Moon–Sun elongation into 30 parts of 12°. Karana divides it into 60 parts of 6°. Nakshatra divides sidereal lunar longitude into 27 parts, and yoga divides the sum of sidereal lunar and solar longitude into 27 parts. Transitions are searched to half-second numerical precision; displayed clock values are rounded to minutes. Numerical precision is not a claim about agreement between traditions.
நகரம், நேர மண்டலம் & உதயம்
Each city uses its listed coordinates, sea-level horizon and IANA time zone. Sunrise and sunset use the standard apparent upper-limb definition, with the solar centre 50 arcminutes below the horizon. Daylight-saving changes are applied by the time-zone database. Moonrise and moonset refer to the sunrise-to-next-sunrise day, with explicit next-day dates.
தமிழ் தேதி & கௌரி நேரங்கள்
A sidereal solar ingress before local sunset starts the Tamil month on that civil date; an ingress after sunset starts it on the next date. The sixty-year cycle is anchored to Prabhava in April 1987. Rahu Kalam, Yamagandam and Kuligai use weekday-specific eighths of daylight. Gowri periods divide daylight and night independently into eight parts using the traditional weekday table. Favorable Gowri periods can overlap other traditionally avoided periods; both are shown.
சோதனை & ஒப்பீடு
Regression tests compare Chennai 8 September 2026 sunrise, sunset and lunar transition values against independent published references, and exercise leap days, local date boundaries and daylight-saving changes. Two-minute tolerance is used for minute-rounded reference transitions. Tamil-date and moonrise conventions differ across publishers; those differences are not hidden by changing astronomical results.