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: 11-14 (86), 11-15 (84), 11-16 (82), 11-17 (80), 11-18 (77) — by astronomy; check the weather when the night is within four days.

2039-11-14astronomy score per night — click a bar for that night2039-12-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-11-14 Mon	86	—	unknown	18:40–21:55 (good, 3.25 h)	71.1° 16:50	10.93	3%	91.2°
2039-11-15 Tue	84	—	unknown	18:40–21:50 (good, 3.17 h)	71.1° 16:45	10.95	0%	81.0°
2039-11-16 Wed	82	—	unknown	18:40–21:50 (good, 3.17 h)	71.1° 16:40	10.98	1%	71.0°
2039-11-17 Thu	80	—	unknown	18:40–21:45 (good, 3.08 h)	71.1° 16:35	11.01	4%	61.8°
2039-11-18 Fri	77	—	unknown	18:40–21:40 (good, 3.0 h)	71.1° 16:35	11.04	10%	54.1°
2039-11-19 Sat	70	—	unknown	18:35–21:35 (good, 3.0 h)	71.1° 16:30	11.06	19%	48.8°
2039-11-20 Sun	60	—	unknown	18:35–21:30 (good, 2.92 h)	71.1° 16:25	11.09	29%	46.5°
2039-11-21 Mon	50	—	unknown	18:35–21:15 (good, 2.67 h)	71.1° 16:20	11.12	39%	47.6°
2039-11-22 Tue	42	—	unknown	18:35–21:00 (good, 2.42 h)	71.1° 16:20	11.14	50%	51.5°
2039-11-23 Wed	36	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 16:15	11.16	61%	57.4°
2039-11-24 Thu	33	—	unknown	18:35–19:40 (good, 1.08 h)	71.1° 16:10	11.19	71%	64.6°
2039-11-25 Fri	31	—	unknown	18:35–19:25 (good, 0.83 h)	71.1° 16:05	11.21	80%	72.6°
2039-11-26 Sat	31	—	unknown	18:35–19:30 (good, 0.92 h)	71.1° 16:00	11.23	87%	80.9°
2039-11-27 Sun	33	—	unknown	18:35–19:50 (good, 1.25 h)	71.1° 16:00	11.25	93%	89.4°
2039-11-28 Mon	36	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 15:55	11.27	97%	97.7°
2039-11-29 Tue	40	—	unknown	18:35–20:35 (good, 2.0 h)	71.1° 15:50	11.29	99%	105.8°
2039-11-30 Wed	43	—	unknown	18:35–20:35 (good, 2.0 h)	71.1° 15:45	11.31	100%	113.4°
2039-12-01 Thu	46	—	unknown	18:35–20:40 (good, 2.08 h)	71.1° 15:40	11.33	99%	120.3°
2039-12-02 Fri	46	—	unknown	18:35–20:35 (good, 2.0 h)	71.1° 15:40	11.35	96%	126.2°
2039-12-03 Sat	51	—	unknown	18:35–20:35 (good, 2.0 h)	71.1° 15:35	11.36	91%	130.6°
2039-12-04 Sun	51	—	unknown	18:35–20:30 (good, 1.92 h)	71.1° 15:30	11.38	85%	133.1°
2039-12-05 Mon	50	—	unknown	18:35–20:35 (good, 2.0 h)	71.1° 15:25	11.39	77%	133.3°
2039-12-06 Tue	48	—	unknown	18:35–20:30 (good, 1.92 h)	71.1° 15:25	11.41	69%	131.3°
2039-12-07 Wed	46	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:20	11.42	59%	127.0°
2039-12-08 Thu	45	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 15:15	11.43	49%	121.0°
2039-12-09 Fri	44	—	unknown	18:35–20:15 (good, 1.67 h)	71.1° 15:10	11.44	39%	113.5°
2039-12-10 Sat	42	—	unknown	18:35–20:15 (good, 1.67 h)	71.1° 15:05	11.45	29%	104.9°
2039-12-11 Sun	40	—	unknown	18:35–20:10 (good, 1.58 h)	71.1° 15:05	11.46	19%	95.5°
2039-12-12 Mon	39	—	unknown	18:35–20:05 (good, 1.5 h)	71.1° 15:00	11.47	11%	85.7°
2039-12-13 Tue	38	—	unknown	18:35–20:00 (good, 1.42 h)	71.1° 14:55	11.48	5%	75.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-11-14&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.