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: 11-10 (84), 11-11 (77), 11-12 (66), 11-25 (63), 11-26 (63) — by astronomy; check the weather when the night is within four days.

2037-11-10astronomy score per night — click a bar for that night2037-12-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-11-10 Tue	84	—	unknown	18:45–22:10 (good, 3.42 h)	71.1° 17:05	10.82	15%	51.2°
2037-11-11 Wed	77	—	unknown	18:40–22:05 (good, 3.42 h)	71.1° 17:00	10.85	23%	46.0°
2037-11-12 Thu	66	—	unknown	18:40–22:00 (good, 3.33 h)	71.1° 16:55	10.88	32%	43.6°
2037-11-13 Fri	55	—	unknown	18:40–21:40 (good, 3.0 h)	71.1° 16:50	10.91	42%	44.2°
2037-11-14 Sat	47	—	unknown	18:40–21:30 (good, 2.83 h)	71.1° 16:45	10.94	52%	47.3°
2037-11-15 Sun	41	—	unknown	18:40–20:40 (good, 2.0 h)	71.1° 16:45	10.97	61%	52.4°
2037-11-16 Mon	37	—	unknown	18:40–19:55 (good, 1.25 h)	71.1° 16:40	11.0	70%	58.9°
2037-11-17 Tue	35	—	unknown	18:40–19:35 (good, 0.92 h)	71.1° 16:35	11.02	78%	66.3°
2037-11-18 Wed	35	—	unknown	18:35–19:40 (good, 1.08 h)	71.1° 16:30	11.05	86%	74.4°
2037-11-19 Thu	37	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 16:30	11.08	92%	82.9°
2037-11-20 Fri	40	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 16:25	11.1	96%	91.6°
2037-11-21 Sat	45	—	unknown	18:35–20:55 (good, 2.33 h)	71.1° 16:20	11.13	99%	100.4°
2037-11-22 Sun	51	—	unknown	18:35–21:00 (good, 2.42 h)	71.1° 16:15	11.15	100%	109.1°
2037-11-23 Mon	56	—	unknown	18:35–21:05 (good, 2.5 h)	71.1° 16:10	11.18	99%	117.5°
2037-11-24 Tue	58	—	unknown	18:35–21:05 (good, 2.5 h)	71.1° 16:10	11.2	96%	125.0°
2037-11-25 Wed	63	—	unknown	18:35–21:00 (good, 2.42 h)	71.1° 16:05	11.22	91%	131.2°
2037-11-26 Thu	63	—	unknown	18:35–21:00 (good, 2.42 h)	71.1° 16:00	11.24	84%	135.3°
2037-11-27 Fri	63	—	unknown	18:35–21:00 (good, 2.42 h)	71.1° 15:55	11.26	75%	136.4°
2037-11-28 Sat	61	—	unknown	18:35–21:00 (good, 2.42 h)	71.1° 15:50	11.28	65%	134.1°
2037-11-29 Sun	59	—	unknown	18:35–20:55 (good, 2.33 h)	71.1° 15:50	11.3	54%	129.0°
2037-11-30 Mon	58	—	unknown	18:35–20:50 (good, 2.25 h)	71.1° 15:45	11.32	42%	121.5°
2037-12-01 Tue	56	—	unknown	18:35–20:45 (good, 2.17 h)	71.1° 15:40	11.34	31%	112.6°
2037-12-02 Wed	54	—	unknown	18:35–20:45 (good, 2.17 h)	71.1° 15:35	11.35	21%	102.6°
2037-12-03 Thu	52	—	unknown	18:35–20:40 (good, 2.08 h)	71.1° 15:35	11.37	12%	92.3°
2037-12-04 Fri	51	—	unknown	18:35–20:35 (good, 2.0 h)	71.1° 15:30	11.38	6%	81.8°
2037-12-05 Sat	49	—	unknown	18:35–20:30 (good, 1.92 h)	71.1° 15:25	11.4	2%	71.6°
2037-12-06 Sun	48	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:20	11.41	0%	62.2°
2037-12-07 Mon	46	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:15	11.42	1%	54.1°
2037-12-08 Tue	44	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 15:15	11.44	5%	48.0°
2037-12-09 Wed	40	—	unknown	18:35–20:15 (good, 1.67 h)	71.1° 15:10	11.45	10%	44.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-11-10&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.