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: 10-16 (100), 10-17 (100), 10-18 (100), 10-19 (100), 10-20 (100) — by astronomy; check the weather when the night is within four days.

2030-10-11astronomy score per night — click a bar for that night2030-11-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2030-10-26 Sat	100	—	unknown	20:00–04:55 (good, 9.92 h)	89.7° 23:45	10.28	0%	148.9°
2030-10-27 Sun	100	—	unknown	19:00–04:50 (good, 9.83 h)	89.7° 22:40	10.32	2%	142.4°
2030-10-28 Mon	100	—	unknown	18:55–04:45 (good, 9.83 h)	89.6° 22:35	10.35	6%	132.5°
2030-10-29 Tue	100	—	unknown	18:55–04:40 (good, 9.75 h)	89.5° 22:35	10.39	13%	120.9°
2030-10-30 Wed	100	—	unknown	18:55–04:35 (good, 9.67 h)	89.6° 22:30	10.43	22%	108.6°
2030-10-31 Thu	100	—	unknown	18:55–04:35 (good, 9.67 h)	89.7° 22:25	10.47	32%	96.3°
2030-11-01 Fri	100	—	unknown	18:50–04:30 (good, 9.67 h)	89.7° 22:20	10.5	44%	84.1°
2030-11-02 Sat	100	—	unknown	18:50–04:25 (good, 9.58 h)	89.6° 22:15	10.54	55%	72.3°
2030-11-03 Sun	99	—	unknown	18:50–04:20 (good, 9.5 h)	89.5° 22:15	10.57	65%	61.0°
2030-11-04 Mon	91	—	unknown	21:50–04:20 (good, 6.5 h)	89.7° 22:10	10.61	75%	50.6°
2030-11-05 Tue	83	—	unknown	03:10–04:15 (good, 1.08 h)	89.7° 22:05	10.64	83%	41.4°
2030-11-06 Wed	55	—	unknown	18:45–04:45 (marginal, 10.0 h)	89.7° 22:00	10.68	90%	34.2°
2030-11-07 Thu	35	—	unknown	23:10–04:15 (marginal, 5.08 h)	89.5° 21:55	10.71	95%	30.3°
2030-11-08 Fri	31	—	unknown	18:45–21:05 (marginal, 2.33 h)	89.6° 21:55	10.74	98%	30.7°
2030-11-09 Sat	37	—	unknown	18:45–22:05 (marginal, 3.33 h)	89.7° 21:50	10.78	100%	35.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-10-11&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.