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: 11-19 (100), 11-20 (100), 11-21 (100), 11-22 (100), 11-23 (100) — by astronomy; check the weather when the night is within four days.

2041-11-19astronomy score per night — click a bar for that night2041-12-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-11-19 Tue	100	—	unknown	18:35–03:20 (good, 8.75 h)	89.8° 21:10	11.08	14%	142.4°
2041-11-20 Wed	100	—	unknown	18:35–03:15 (good, 8.67 h)	89.8° 21:05	11.1	8%	145.7°
2041-11-21 Thu	100	—	unknown	18:35–03:10 (good, 8.58 h)	89.7° 21:00	11.13	3%	145.3°
2041-11-22 Fri	100	—	unknown	18:35–03:05 (good, 8.5 h)	89.5° 21:00	11.15	1%	141.2°
2041-11-23 Sat	100	—	unknown	18:35–03:05 (good, 8.5 h)	89.7° 20:55	11.18	0%	134.1°
2041-11-24 Sun	100	—	unknown	18:35–03:00 (good, 8.42 h)	89.8° 20:50	11.2	2%	125.0°
2041-11-25 Mon	100	—	unknown	18:35–02:55 (good, 8.33 h)	89.8° 20:45	11.22	6%	114.8°
2041-11-26 Tue	100	—	unknown	18:35–02:50 (good, 8.25 h)	89.6° 20:40	11.24	12%	103.8°
2041-11-27 Wed	100	—	unknown	18:35–02:45 (good, 8.17 h)	89.6° 20:40	11.26	20%	92.5°
2041-11-28 Thu	100	—	unknown	18:35–02:45 (good, 8.17 h)	89.7° 20:35	11.28	29%	81.0°
2041-11-29 Fri	100	—	unknown	18:35–02:40 (good, 8.08 h)	89.8° 20:30	11.3	40%	69.6°
2041-11-30 Sat	95	—	unknown	18:35–02:35 (good, 8.0 h)	89.7° 20:25	11.32	51%	58.5°
2041-12-01 Sun	86	—	unknown	18:35–02:30 (good, 7.92 h)	89.6° 20:20	11.34	62%	48.4°
2041-12-02 Mon	66	—	unknown	02:15–02:25 (good, 0.17 h)	89.6° 20:20	11.35	73%	40.0°
2041-12-03 Tue	45	—	unknown	18:35–02:45 (marginal, 8.17 h)	89.8° 20:15	11.37	83%	34.8°
2041-12-04 Wed	33	—	unknown	18:35–02:20 (marginal, 7.75 h)	89.8° 20:10	11.38	90%	34.3°
2041-12-05 Thu	31	—	unknown	18:35–01:50 (marginal, 7.25 h)	89.7° 20:05	11.4	96%	38.6°
2041-12-06 Fri	38	—	unknown	18:35–01:30 (marginal, 6.92 h)	89.5° 20:00	11.41	99%	46.3°
2041-12-07 Sat	52	—	unknown	18:35–01:45 (marginal, 7.17 h)	89.7° 20:00	11.42	100%	55.8°
2041-12-08 Sun	68	—	unknown	18:35–20:25 (good, 1.83 h)	89.8° 19:55	11.44	98%	66.1°
2041-12-09 Mon	77	—	unknown	18:35–22:55 (good, 4.33 h)	89.8° 19:50	11.45	94%	76.6°
2041-12-10 Tue	100	—	unknown	18:35–00:20 (good, 5.75 h)	89.6° 19:45	11.46	89%	87.2°
2041-12-11 Wed	100	—	unknown	18:35–01:25 (good, 6.83 h)	89.6° 19:45	11.47	82%	97.5°
2041-12-12 Thu	100	—	unknown	18:35–01:30 (good, 6.92 h)	89.7° 19:40	11.47	74%	107.5°
2041-12-13 Fri	100	—	unknown	18:35–01:35 (good, 7.0 h)	89.8° 19:35	11.48	65%	117.0°
2041-12-14 Sat	100	—	unknown	18:35–01:35 (good, 7.0 h)	89.7° 19:30	11.49	56%	126.0°
2041-12-15 Sun	100	—	unknown	18:35–01:30 (good, 6.92 h)	89.6° 19:25	11.49	47%	134.1°
2041-12-16 Mon	100	—	unknown	18:35–01:30 (good, 6.92 h)	89.6° 19:25	11.5	37%	140.7°
2041-12-17 Tue	100	—	unknown	18:35–01:30 (good, 6.92 h)	89.8° 19:20	11.5	28%	145.1°
2041-12-18 Wed	100	—	unknown	18:35–01:25 (good, 6.83 h)	89.8° 19:15	11.5	20%	146.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-11-19&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.