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: 01-25 (99), 01-26 (97), 01-27 (95), 01-28 (93), 01-29 (90) — by astronomy; check the weather when the night is within four days.

2041-01-25astronomy score per night — click a bar for that night2041-02-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-01-25 Fri	99	—	unknown	19:05–22:55 (good, 3.83 h)	89.8° 16:45	10.96	45%	143.3°
2041-01-26 Sat	97	—	unknown	19:10–22:50 (good, 3.67 h)	89.7° 16:40	10.93	34%	138.1°
2041-01-27 Sun	95	—	unknown	19:10–22:45 (good, 3.58 h)	89.6° 16:35	10.9	24%	130.0°
2041-01-28 Mon	93	—	unknown	19:10–22:40 (good, 3.5 h)	89.6° 16:35	10.87	15%	120.0°
2041-01-29 Tue	90	—	unknown	19:10–22:40 (good, 3.5 h)	89.7° 16:30	10.84	8%	108.7°
2041-01-30 Wed	88	—	unknown	19:10–22:35 (good, 3.42 h)	89.8° 16:25	10.81	3%	96.6°
2041-01-31 Thu	85	—	unknown	19:15–22:30 (good, 3.25 h)	89.7° 16:20	10.78	0%	84.1°
2041-02-01 Fri	83	—	unknown	19:15–22:25 (good, 3.17 h)	89.5° 16:15	10.75	1%	71.8°
2041-02-02 Sat	80	—	unknown	19:15–22:20 (good, 3.08 h)	89.6° 16:15	10.71	5%	60.0°
2041-02-03 Sun	73	—	unknown	19:15–22:20 (good, 3.08 h)	89.8° 16:10	10.68	11%	49.5°
2041-02-04 Mon	63	—	unknown	19:20–22:15 (good, 2.92 h)	89.8° 16:05	10.64	19%	41.1°
2041-02-05 Tue	51	—	unknown	19:20–21:55 (good, 2.58 h)	89.6° 16:00	10.61	29%	36.1°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-01-25&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.