drik-panchanga

Observational Indian lunisolar calendar (Hindu Drig-ganita / Drik Panchanga) using the Swiss Ephemeris.

2.0.0 installs the core library modules panchanga.py and datetime_helper.py (dates, time zones, clock formatting), plus the PDF calendar generators behind the [pdf] extra:

pip install drik-panchanga          # core library only
pip install "drik-panchanga[pdf]"   # + reportlab, PDF console scripts

With the [pdf] extra, two console commands are available:

• drik-panchanga-short — one-page A4 landscape panchanga for one lunar year
• drik-panchanga-long — A4 portrait wall calendar, one page per month of the lunar year

--start YYYY prints the cāndramāna year whose Ugadi falls in Gregorian year YYYY, from the month containing Ugadi through the month containing the last Phālguna day (12–14 months; years -3300 ... 3300). BCE years take a leading minus on the flag value (--start=-0500). Use --place LAT,LON,TZ when the city is missing from the catalog.

drik-panchanga-short --city "Bengaluru, IN" --start 2026
drik-panchanga-short --place -13.4,70,5.5 --start 2026  # lat, lon, UTC offset hours
drik-panchanga-long  --city Ujjain --start=-500

Changes in 2.0.0

Breaking relative to 1.0.0:

• Date, gregorian_to_jd, format_hms, format_local_hm and the other civil-date / time-zone helpers live in datetime_helper, not panchanga.
• Event functions return UT Julian days. Format for display with format_local_hm (IANA zone, DST-aware) or format_hms_from_jd (fixed offset). Do not treat the second element of tithi / nakshatra as a local clock triple.
• CLI --start is an astronomical year YYYY (the lunar year of that year's Ugadi), not YYYY-MM.
• Prefer set_coordinate_selection("citra") to set the ayanāṃśa and sidereal mode together. set_chosen_ayanamsa only sets the key and leaves a prior tropical mode in place.

Also new: --place LAT,LON,TZ, Hindu-day moonrise / moonset, polar transit fallbacks, and BCE years through about 5000 BCE.

Ephemeris data

Swiss Ephemeris needs .se1 data files. Either set SE_EPHE_PATH to a directory that contains them, or place them in the default location used by this library:

• Linux / macOS: ~/.local/share/swisseph (or $XDG_DATA_HOME/swisseph)
• Windows: %LOCALAPPDATA%\swisseph

Usage

import panchanga
from datetime_helper import Date, format_hms, format_local_hm, gregorian_to_jd

panchanga.set_coordinate_selection("citra")  # ayanāṃśa key + sidereal mode
place = panchanga.Place(12.972, 77.594, +5.5)  # lat, lon, UTC offset hours that day
day = Date(2026, 1, 15)
jd = gregorian_to_jd(day)
tithi, end = panchanga.tithi(jd, place)[:2]     # end is a UT Julian day
print(tithi, format_local_hm(end, "Asia/Kolkata", anchor_civil=day))  # 27 20:17
print(panchanga.nakshatra(jd, place))
print(panchanga.masa(jd, place, amanta=True))   # or amanta=False for pūrṇimānta
print(panchanga.moonrise(jd, place))  # UT JD in [sunrise, next sunrise), or None
print(format_hms([23, 59, 30]))  # "24:00" — never wraps to 00:00

Event times are UT Julian days; format_local_hm shows them as hours past the civil day's midnight at the offset in force at each instant (DST-aware), running past 24:00 when the Hindu day (sunrise to sunrise) does. moonrise / moonset use that window; the low-level moonrise_jd helper is first-after-local-midnight only.

For tropical (sāyana) values instead of sidereal, call set_coordinate_mode("tropical") before computing; reset with set_coordinate_mode("sidereal"):

panchanga.set_coordinate_mode("tropical")
print(panchanga.tithi(jd, place))          # tithi from tropical longitudes
print(panchanga.masa(jd, place, amanta=True))
panchanga.set_coordinate_mode("sidereal")

Full source, web UI, festival rules, and PDF calendar live in the GitHub repository.

License

GNU Affero General Public License v3 or later (AGPL-3.0-or-later).