Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for Andromeda Galaxy: 04-25 (1), 04-26 (1), 04-27 (1) — by astronomy; check the weather when the night is within four days.

2026-03-29astronomy score per night — click a bar for that night2026-04-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2026-03-29 Sun	0	0	0	—	89.5° 13:40	8.25	90%	117.2°
2026-03-30 Mon	0	0	0	—	89.7° 13:35	8.19	95%	127.9°
2026-03-31 Tue	0	0	0	—	89.7° 13:30	8.14	99%	137.5°
2026-04-01 Wed	0	0	0	—	89.7° 13:25	8.08	100%	145.3°
2026-04-02 Thu	0	0	0	—	89.5° 13:20	8.03	99%	149.9°
2026-04-03 Fri	0	0	0	—	89.6° 13:20	7.97	96%	150.2°
2026-04-04 Sat	0	0	0	—	89.7° 13:15	7.92	92%	146.2°
2026-04-05 Sun	0	0	0	—	89.7° 13:10	7.86	86%	139.3°
2026-04-06 Mon	0	58	0	—	89.6° 13:05	7.8	79%	130.8°
2026-04-07 Tue	0	100	0	—	89.5° 13:00	7.75	71%	121.4°
2026-04-08 Wed	0	46	0	—	89.6° 13:00	7.69	62%	111.5°
2026-04-09 Thu	0	0	0	—	89.7° 12:55	7.64	53%	101.2°
2026-04-10 Fri	0	0	0	—	89.7° 12:50	7.58	43%	90.7°
2026-04-11 Sat	0	0	0	—	89.6° 12:45	7.52	33%	79.9°
2026-04-12 Sun	0	0	0	—	89.5° 12:45	7.47	24%	68.9°
2026-04-13 Mon	0	0	0	—	89.6° 12:40	7.41	16%	57.9°
2026-04-14 Tue	0	0	0	—	89.7° 12:35	7.35	9%	47.3°
2026-04-15 Wed	0	0	0	—	89.7° 12:30	7.29	3%	37.7°
2026-04-16 Thu	0	72	0	—	89.5° 12:25	7.24	0%	31.0°
2026-04-17 Fri	0	77	0	—	89.6° 12:25	7.18	0%	29.6°
2026-04-18 Sat	0	97	0	—	89.7° 12:20	7.12	3%	34.6°
2026-04-19 Sun	0	54	0	—	89.7° 12:15	7.06	9%	43.7°
2026-04-20 Mon	0	36	0	—	89.6° 12:10	7.0	16%	54.9°
2026-04-21 Tue	0	0	0	—	89.5° 12:05	6.95	26%	67.0°
2026-04-22 Wed	0	0	0	—	89.7° 12:00	6.89	37%	79.2°
2026-04-23 Thu	0	0	0	—	89.7° 12:00	6.83	48%	91.4°
2026-04-24 Fri	0	100	0	—	89.6° 11:50	6.77	59%	103.3°
2026-04-25 Sat	1	100	1	—	89.5° 11:50	6.71	69%	114.7°
2026-04-26 Sun	1	100	1	—	89.6° 11:45	6.65	78%	125.5°
2026-04-27 Mon	1	31	0	—	89.7° 11:40	6.6	86%	135.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2026-03-29&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.