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: 09-26 (100), 09-27 (100), 09-28 (100), 09-29 (100), 09-30 (100) — by astronomy; check the weather when the night is within four days.

2030-09-26astronomy score per night — click a bar for that night2030-10-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-09-26 Thu	100	—	unknown	20:45–05:45 (good, 9.0 h)	89.5° 01:40	8.94	0%	139.9°
2030-09-27 Fri	100	—	unknown	20:45–05:45 (good, 9.0 h)	89.6° 01:40	8.99	0%	147.2°
2030-09-28 Sat	100	—	unknown	20:45–05:45 (good, 9.0 h)	89.7° 01:35	9.04	3%	150.1°
2030-09-29 Sun	100	—	unknown	20:40–05:45 (good, 9.08 h)	89.7° 01:30	9.08	8%	147.0°
2030-09-30 Mon	100	—	unknown	20:40–05:50 (good, 9.17 h)	89.6° 01:25	9.13	16%	139.2°
2030-10-01 Tue	100	—	unknown	20:40–05:50 (good, 9.17 h)	89.5° 01:25	9.18	25%	128.8°
2030-10-02 Wed	100	—	unknown	20:35–05:50 (good, 9.25 h)	89.7° 01:20	9.23	36%	117.3°
2030-10-03 Thu	100	—	unknown	20:35–05:50 (good, 9.25 h)	89.7° 01:15	9.28	47%	105.4°
2030-10-04 Fri	100	—	unknown	20:35–05:50 (good, 9.25 h)	89.7° 01:10	9.32	58%	93.3°
2030-10-05 Sat	100	—	unknown	20:30–05:55 (good, 9.42 h)	89.5° 01:05	9.37	69%	81.4°
2030-10-06 Sun	100	—	unknown	20:45–05:55 (good, 9.17 h)	89.6° 01:05	9.42	79%	69.7°
2030-10-07 Mon	96	—	unknown	00:40–05:55 (good, 5.25 h)	89.7° 01:00	9.46	87%	58.6°
2030-10-08 Tue	88	—	unknown	03:50–05:55 (good, 2.08 h)	89.7° 00:55	9.51	93%	48.3°
2030-10-09 Wed	52	—	unknown	20:25–06:00 (marginal, 9.58 h)	89.7° 00:50	9.56	97%	39.4°
2030-10-10 Thu	38	—	unknown	01:50–06:00 (marginal, 4.17 h)	89.5° 00:45	9.6	100%	32.8°
2030-10-11 Fri	34	—	unknown	20:20–23:15 (marginal, 2.92 h)	89.6° 00:45	9.65	100%	30.0°
2030-10-12 Sat	40	—	unknown	20:20–00:20 (marginal, 4.0 h)	89.7° 00:40	9.69	98%	31.7°
2030-10-13 Sun	54	—	unknown	20:20–06:00 (marginal, 9.67 h)	89.7° 00:35	9.74	94%	37.1°
2030-10-14 Mon	89	—	unknown	20:15–22:00 (good, 1.75 h)	89.6° 00:30	9.78	89%	44.8°
2030-10-15 Tue	94	—	unknown	20:15–00:10 (good, 3.92 h)	89.5° 00:30	9.82	82%	53.7°
2030-10-16 Wed	100	—	unknown	20:15–03:25 (good, 7.17 h)	89.7° 00:25	9.87	75%	63.3°
2030-10-17 Thu	100	—	unknown	20:10–04:55 (good, 8.75 h)	89.7° 00:20	9.91	66%	73.3°
2030-10-18 Fri	100	—	unknown	20:10–05:55 (good, 9.75 h)	89.7° 00:15	9.95	57%	83.5°
2030-10-19 Sat	100	—	unknown	20:10–06:05 (good, 9.92 h)	89.6° 00:10	9.99	47%	94.0°
2030-10-20 Sun	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.5° 00:10	10.03	37%	104.6°
2030-10-21 Mon	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.7° 00:05	10.08	28%	115.3°
2030-10-22 Tue	100	—	unknown	20:05–06:05 (good, 10.0 h)	89.7° 00:00	10.12	19%	125.9°
2030-10-23 Wed	100	—	unknown	20:05–06:05 (good, 10.0 h)	89.7° 23:55	10.16	11%	136.0°
2030-10-24 Thu	100	—	unknown	20:00–06:00 (good, 10.0 h)	89.5° 23:50	10.2	5%	144.5°
2030-10-25 Fri	100	—	unknown	20:00–05:55 (good, 9.92 h)	89.6° 23:50	10.24	1%	149.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-09-26&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.