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: 11-18 (100), 11-19 (100), 11-20 (100), 11-21 (100), 11-22 (100) — by astronomy; check the weather when the night is within four days.

2030-11-18astronomy score per night — click a bar for that night2030-12-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-11-18 Mon	100	—	unknown	18:40–03:15 (good, 8.58 h)	89.7° 21:15	11.04	44%	122.1°
2030-11-19 Tue	100	—	unknown	18:35–03:15 (good, 8.67 h)	89.7° 21:10	11.07	34%	132.2°
2030-11-20 Wed	100	—	unknown	18:35–03:15 (good, 8.67 h)	89.7° 21:05	11.1	24%	141.3°
2030-11-21 Thu	100	—	unknown	18:35–03:10 (good, 8.58 h)	89.5° 21:00	11.12	16%	148.0°
2030-11-22 Fri	100	—	unknown	18:35–03:05 (good, 8.5 h)	89.6° 21:00	11.14	8%	150.0°
2030-11-23 Sat	100	—	unknown	18:35–03:05 (good, 8.5 h)	89.7° 20:55	11.17	3%	146.0°
2030-11-24 Sun	100	—	unknown	18:35–03:00 (good, 8.42 h)	89.7° 20:50	11.19	0%	137.2°
2030-11-25 Mon	100	—	unknown	18:35–02:55 (good, 8.33 h)	89.6° 20:45	11.21	1%	126.0°
2030-11-26 Tue	100	—	unknown	18:35–02:50 (good, 8.25 h)	89.5° 20:45	11.24	4%	113.6°
2030-11-27 Wed	100	—	unknown	18:35–02:45 (good, 8.17 h)	89.6° 20:40	11.26	10%	100.7°
2030-11-28 Thu	100	—	unknown	18:35–02:45 (good, 8.17 h)	89.7° 20:35	11.28	18%	88.0°
2030-11-29 Fri	100	—	unknown	18:35–02:40 (good, 8.08 h)	89.7° 20:30	11.3	28%	75.6°
2030-11-30 Sat	100	—	unknown	18:35–02:35 (good, 8.0 h)	89.6° 20:25	11.31	39%	63.9°
2030-12-01 Sun	93	—	unknown	18:35–02:30 (good, 7.92 h)	89.5° 20:25	11.33	50%	53.0°
2030-12-02 Mon	85	—	unknown	18:35–02:30 (good, 7.92 h)	89.7° 20:20	11.35	60%	43.3°
2030-12-03 Tue	70	—	unknown	02:05–02:25 (good, 0.33 h)	89.7° 20:15	11.36	70%	35.6°
2030-12-04 Wed	47	—	unknown	18:35–02:45 (marginal, 8.17 h)	89.7° 20:10	11.38	78%	30.8°
2030-12-05 Thu	33	—	unknown	18:35–02:25 (marginal, 7.83 h)	89.5° 20:05	11.39	86%	30.2°
2030-12-06 Fri	29	—	unknown	18:35–02:00 (marginal, 7.42 h)	89.6° 20:05	11.41	92%	33.8°
2030-12-07 Sat	32	—	unknown	18:35–01:45 (marginal, 7.17 h)	89.7° 20:00	11.42	96%	40.4°
2030-12-08 Sun	41	—	unknown	18:35–01:40 (marginal, 7.08 h)	89.7° 19:55	11.43	99%	48.7°
2030-12-09 Mon	55	—	unknown	18:00–01:45 (marginal, 7.75 h)	89.6° 19:50	11.44	100%	58.0°
2030-12-10 Tue	69	—	unknown	18:35–20:35 (good, 2.0 h)	89.5° 19:45	11.45	99%	67.8°
2030-12-11 Wed	77	—	unknown	18:35–22:50 (good, 4.25 h)	89.6° 19:45	11.46	96%	77.9°
2030-12-12 Thu	100	—	unknown	18:35–00:10 (good, 5.58 h)	89.7° 19:40	11.47	92%	88.2°
2030-12-13 Fri	100	—	unknown	18:35–01:15 (good, 6.67 h)	89.7° 19:35	11.48	86%	98.6°
2030-12-14 Sat	100	—	unknown	18:35–01:25 (good, 6.83 h)	89.6° 19:30	11.49	79%	109.0°
2030-12-15 Sun	100	—	unknown	18:35–01:25 (good, 6.83 h)	89.5° 19:30	11.49	70%	119.2°
2030-12-16 Mon	100	—	unknown	18:35–01:25 (good, 6.83 h)	89.7° 19:25	11.5	61%	129.2°
2030-12-17 Tue	100	—	unknown	18:35–01:25 (good, 6.83 h)	89.7° 19:20	11.5	51%	138.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-11-18&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.