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 HD 189733: 11-15 (84), 11-16 (82), 11-17 (75), 11-18 (66), 11-19 (56) — by astronomy; check the weather when the night is within four days.

2031-11-15astronomy score per night — click a bar for that night2031-12-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-11-15 Sat	84	—	unknown	18:40–21:50 (good, 3.17 h)	71.1° 16:45	10.95	1%	68.3°
2031-11-16 Sun	82	—	unknown	18:40–21:45 (good, 3.08 h)	71.1° 16:40	10.98	6%	57.6°
2031-11-17 Mon	75	—	unknown	18:40–21:45 (good, 3.08 h)	71.1° 16:35	11.01	12%	48.2°
2031-11-18 Tue	66	—	unknown	18:40–21:40 (good, 3.0 h)	71.1° 16:35	11.04	21%	40.9°
2031-11-19 Wed	56	—	unknown	18:35–21:25 (good, 2.83 h)	71.1° 16:30	11.06	31%	37.2°
2031-11-20 Thu	45	—	unknown	18:35–21:10 (good, 2.58 h)	71.1° 16:25	11.09	42%	38.1°
2031-11-21 Fri	36	—	unknown	18:35–20:15 (good, 1.67 h)	71.1° 16:20	11.11	54%	43.1°
2031-11-22 Sat	30	—	unknown	18:35–19:05 (good, 0.5 h)	71.1° 16:20	11.14	64%	50.8°
2031-11-23 Sun	27	—	unknown	18:35–18:40 (good, 0.08 h)	71.1° 16:15	11.16	75%	60.0°
2031-11-24 Mon	27	—	unknown	18:35–18:45 (good, 0.17 h)	71.1° 16:10	11.19	83%	70.1°
2031-11-25 Tue	29	—	unknown	18:35–19:15 (good, 0.67 h)	71.1° 16:05	11.21	90%	80.4°
2031-11-26 Wed	33	—	unknown	18:35–19:50 (good, 1.25 h)	71.1° 16:00	11.23	96%	90.8°
2031-11-27 Thu	38	—	unknown	18:35–20:35 (good, 2.0 h)	71.1° 16:00	11.25	99%	101.0°
2031-11-28 Fri	44	—	unknown	18:35–20:40 (good, 2.08 h)	71.1° 15:55	11.27	100%	110.9°
2031-11-29 Sat	49	—	unknown	18:35–20:45 (good, 2.17 h)	71.1° 15:50	11.29	99%	120.1°
2031-11-30 Sun	49	—	unknown	18:35–20:45 (good, 2.17 h)	71.1° 15:45	11.31	96%	128.5°
2031-12-01 Mon	54	—	unknown	18:35–20:40 (good, 2.08 h)	71.1° 15:40	11.33	92%	135.5°
2031-12-02 Tue	54	—	unknown	18:35–20:40 (good, 2.08 h)	71.1° 15:40	11.34	86%	140.5°
2031-12-03 Wed	54	—	unknown	18:35–20:40 (good, 2.08 h)	71.1° 15:35	11.36	79%	142.9°
2031-12-04 Thu	52	—	unknown	18:35–20:35 (good, 2.0 h)	71.1° 15:30	11.38	70%	142.1°
2031-12-05 Fri	50	—	unknown	18:35–20:35 (good, 2.0 h)	71.1° 15:25	11.39	62%	138.3°
2031-12-06 Sat	48	—	unknown	18:35–20:30 (good, 1.92 h)	71.1° 15:25	11.4	52%	132.2°
2031-12-07 Sun	46	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:20	11.42	42%	124.5°
2031-12-08 Mon	45	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 15:15	11.43	33%	115.5°
2031-12-09 Tue	44	—	unknown	18:35–20:15 (good, 1.67 h)	71.1° 15:10	11.44	23%	105.7°
2031-12-10 Wed	42	—	unknown	18:35–20:15 (good, 1.67 h)	71.1° 15:05	11.45	15%	95.2°
2031-12-11 Thu	40	—	unknown	18:35–20:10 (good, 1.58 h)	71.1° 15:05	11.46	8%	84.2°
2031-12-12 Fri	38	—	unknown	18:35–20:05 (good, 1.5 h)	71.1° 15:00	11.47	3%	73.0°
2031-12-13 Sat	38	—	unknown	18:35–20:00 (good, 1.42 h)	71.1° 14:55	11.48	0%	61.9°
2031-12-14 Sun	36	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 14:50	11.48	0%	51.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-11-15&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.