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: 02-18 (42), 02-19 (42), 02-06 (40), 02-20 (40), 02-16 (39) — by astronomy; check the weather when the night is within four days.

2041-02-06astronomy score per night — click a bar for that night2041-03-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-02-06 Wed	40	—	unknown	19:20–21:40 (good, 2.33 h)	89.5° 16:00	10.57	39%	35.4°
2041-02-07 Thu	31	—	unknown	19:20–20:05 (good, 0.75 h)	89.7° 15:55	10.54	50%	38.9°
2041-02-08 Fri	25	—	unknown	19:20–22:20 (marginal, 3.0 h)	89.8° 15:50	10.5	60%	45.3°
2041-02-09 Sat	21	—	unknown	19:25–22:10 (marginal, 2.75 h)	89.7° 15:45	10.46	69%	53.4°
2041-02-10 Sun	20	—	unknown	19:25–22:05 (marginal, 2.67 h)	89.6° 15:40	10.43	78%	62.3°
2041-02-11 Mon	21	—	unknown	19:25–22:00 (marginal, 2.58 h)	89.6° 15:40	10.39	85%	71.7°
2041-02-12 Tue	23	—	unknown	19:25–22:00 (marginal, 2.58 h)	89.7° 15:35	10.35	91%	81.3°
2041-02-13 Wed	26	—	unknown	19:30–20:05 (good, 0.58 h)	89.8° 15:30	10.31	96%	91.0°
2041-02-14 Thu	31	—	unknown	19:30–20:55 (good, 1.42 h)	89.7° 15:25	10.27	99%	100.6°
2041-02-15 Fri	35	—	unknown	19:30–21:10 (good, 1.67 h)	89.5° 15:20	10.23	100%	110.1°
2041-02-16 Sat	39	—	unknown	19:30–21:15 (good, 1.75 h)	89.6° 15:20	10.19	99%	119.3°
2041-02-17 Sun	38	—	unknown	19:35–21:10 (good, 1.58 h)	89.8° 15:15	10.15	97%	127.9°
2041-02-18 Mon	42	—	unknown	19:35–21:10 (good, 1.58 h)	89.8° 15:10	10.11	93%	135.6°
2041-02-19 Tue	42	—	unknown	19:35–21:15 (good, 1.67 h)	89.6° 15:05	10.07	87%	141.5°
2041-02-20 Wed	40	—	unknown	19:35–21:10 (good, 1.58 h)	89.5° 15:05	10.03	80%	144.7°
2041-02-21 Thu	38	—	unknown	19:35–21:10 (good, 1.58 h)	89.7° 15:00	9.98	71%	144.3°
2041-02-22 Fri	36	—	unknown	19:40–21:05 (good, 1.42 h)	89.8° 14:55	9.94	61%	140.1°
2041-02-23 Sat	35	—	unknown	19:40–21:00 (good, 1.33 h)	89.7° 14:50	9.9	51%	133.0°
2041-02-24 Sun	33	—	unknown	19:40–20:55 (good, 1.25 h)	89.6° 14:45	9.85	40%	123.9°
2041-02-25 Mon	31	—	unknown	19:40–20:50 (good, 1.17 h)	89.6° 14:45	9.81	29%	113.3°
2041-02-26 Tue	29	—	unknown	19:45–20:50 (good, 1.08 h)	89.7° 14:40	9.77	20%	101.9°
2041-02-27 Wed	27	—	unknown	19:45–20:45 (good, 1.0 h)	89.8° 14:35	9.72	11%	89.8°
2041-02-28 Thu	26	—	unknown	19:45–20:40 (good, 0.92 h)	89.7° 14:30	9.68	5%	77.5°
2041-03-01 Fri	25	—	unknown	19:45–20:35 (good, 0.83 h)	89.5° 14:25	9.63	1%	65.5°
2041-03-02 Sat	22	—	unknown	19:50–20:30 (good, 0.67 h)	89.6° 14:25	9.58	0%	54.1°
2041-03-03 Sun	21	—	unknown	19:50–20:30 (good, 0.67 h)	89.8° 14:20	9.54	3%	44.4°
2041-03-04 Mon	18	—	unknown	19:50–20:20 (good, 0.5 h)	89.8° 14:15	9.49	8%	37.5°
2041-03-05 Tue	15	—	unknown	19:50–20:15 (good, 0.42 h)	89.6° 14:10	9.45	15%	34.9°
2041-03-06 Wed	12	—	unknown	19:50–20:00 (good, 0.17 h)	89.5° 14:10	9.4	23%	37.0°
2041-03-07 Thu	8	—	unknown	19:55–20:45 (marginal, 0.83 h)	89.7° 14:05	9.35	33%	42.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-02-06&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.