Files
Jyotisha/scripts/saham_daynight.py
T
jesse-uxGrok (agent loop)Cursor
0bd254cf18 fix(gulika): end the night segment at the real next Hindu sunrise
Upstream 9f9f16b3 and 872eaecf. Saham, Gulika, and Shayanadi opt into Hindu rising. The default window used by rectification and Panchanga stays the apparent-disk one. BUG-1388.

Co-Authored-By: Grok (agent loop)
Co-authored-by: Cursor <cursoragent@cursor.com>
2026-10-18 16:49:12 +08:00

91 lines
3.7 KiB
Python

"""Swiss Ephemeris sunrise/sunset evidence for Saham day/night formula selection."""
from __future__ import annotations
from datetime import datetime
from typing import Any
import swisseph as swe
class SahamDayNightError(ValueError):
pass
def determine_daytime(
moment: datetime,
*,
lat: float,
lon: float,
tz: float,
rising: str = "apparent",
) -> dict[str, Any]:
"""Day/night window.
``rising="apparent"`` is the historical disk-edge window. Rectification and
Panchanga rely on that default and must not pick up Hindu rising.
``rising="hindu"`` is disk-center, no refraction, with the real next
sunrise. Saham day/night, Gulika, and Shayanadi pass it explicitly.
"""
if rising not in ("apparent", "hindu"):
raise SahamDayNightError("unsupported sunrise convention")
if not -90 <= float(lat) <= 90 or not -180 <= float(lon) <= 180:
raise SahamDayNightError("invalid WGS84 latitude/longitude")
local = moment.replace(tzinfo=None)
jd = swe.julday(local.year, local.month, local.day, local.hour + local.minute / 60 + local.second / 3600 - float(tz))
geopos = (float(lon), float(lat), 0.0)
if rising == "apparent":
rise_status, rise = swe.rise_trans(jd - 1.0, swe.SUN, swe.CALC_RISE, geopos)
set_status, sunset = swe.rise_trans(jd - 1.0, swe.SUN, swe.CALC_SET, geopos)
if rise_status != 0 or set_status != 0:
raise SahamDayNightError("sunrise_or_sunset_unavailable_for_location_date")
sunrise_jd, sunset_jd = rise[0], sunset[0]
# Normalize the next daily events around the queried instant.
while sunrise_jd > jd:
sunrise_jd -= 1.0
while sunset_jd > jd:
sunset_jd -= 1.0
is_day = sunrise_jd <= jd < sunset_jd if sunrise_jd < sunset_jd else not (sunset_jd <= jd < sunrise_jd)
return {
"scope": "saham_daynight_swiss",
"status": "computed",
"is_daytime": is_day,
"julian_day_ut": jd,
"sunrise_jd_ut": sunrise_jd,
"sunset_jd_ut": sunset_jd,
"method": "swisseph.rise_trans",
"boundary": "Formula-specific +30 degree exceptions must be applied by the Saham rule layer, not inferred from house placement.",
}
flags = swe.FLG_SWIEPH | swe.FLG_TRUEPOS
def event(after, kind):
status, times = swe.rise_trans(after, swe.SUN, kind | swe.BIT_HINDU_RISING, geopos, flags=flags)
if status != 0:
raise SahamDayNightError("sunrise_or_sunset_unavailable_for_location_date")
return times[0]
# Consecutive rise/set events. Adding one Julian day to a sunrise is not
# the next sunrise, and it moves the night-segment endpoint.
midnight_jd = swe.julday(local.year, local.month, local.day, -float(tz))
sunrise_jd = event(midnight_jd, swe.CALC_RISE)
if sunrise_jd > jd:
midnight_jd -= 1.0
sunrise_jd = event(midnight_jd, swe.CALC_RISE)
next_sunrise_jd = event(midnight_jd + 1.0, swe.CALC_RISE)
sunset_jd = event(midnight_jd, swe.CALC_SET)
if not sunrise_jd <= jd < next_sunrise_jd or not sunrise_jd < sunset_jd < next_sunrise_jd:
raise SahamDayNightError("solar_day_window_unavailable")
is_day = sunrise_jd <= jd < sunset_jd
return {
"scope": "saham_daynight_swiss",
"status": "computed",
"is_daytime": is_day,
"julian_day_ut": jd,
"sunrise_jd_ut": sunrise_jd,
"sunset_jd_ut": sunset_jd,
"next_sunrise_jd_ut": next_sunrise_jd,
"method": "swisseph.rise_trans_hindu_rising",
"boundary": "Formula-specific +30 degree exceptions must be applied by the Saham rule layer, not inferred from house placement.",
}