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: 10-13 (100), 10-14 (100), 10-15 (100), 10-16 (100), 10-17 (100) — by astronomy; check the weather when the night is within four days.

2044-10-13astronomy score per night — click a bar for that night2044-11-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-10-13 Thu	100	—	unknown	20:15–00:55 (good, 4.67 h)	71.1° 19:50	9.76	50%	131.3°
2044-10-14 Fri	100	—	unknown	20:15–00:55 (good, 4.67 h)	71.1° 19:50	9.81	39%	134.8°
2044-10-15 Sat	100	—	unknown	20:15–00:50 (good, 4.58 h)	71.1° 19:45	9.85	28%	134.9°
2044-10-16 Sun	100	—	unknown	20:10–00:45 (good, 4.58 h)	71.1° 19:40	9.89	18%	131.8°
2044-10-17 Mon	100	—	unknown	20:10–00:45 (good, 4.58 h)	71.1° 19:35	9.93	11%	126.0°
2044-10-18 Tue	100	—	unknown	20:10–00:40 (good, 4.5 h)	71.1° 19:30	9.98	5%	118.5°
2044-10-19 Wed	100	—	unknown	20:10–00:35 (good, 4.42 h)	71.1° 19:30	10.02	1%	110.0°
2044-10-20 Thu	100	—	unknown	20:05–00:30 (good, 4.42 h)	71.1° 19:25	10.06	0%	100.9°
2044-10-21 Fri	100	—	unknown	20:05–00:25 (good, 4.33 h)	71.1° 19:20	10.1	1%	91.8°
2044-10-22 Sat	100	—	unknown	20:05–00:25 (good, 4.33 h)	71.1° 19:15	10.14	4%	82.7°
2044-10-23 Sun	100	—	unknown	20:05–00:20 (good, 4.25 h)	71.1° 19:15	10.18	9%	74.1°
2044-10-24 Mon	100	—	unknown	20:00–00:15 (good, 4.25 h)	71.1° 19:10	10.22	15%	66.0°
2044-10-25 Tue	100	—	unknown	20:00–00:10 (good, 4.17 h)	71.1° 19:05	10.26	23%	58.7°
2044-10-26 Wed	93	—	unknown	20:00–00:05 (good, 4.08 h)	71.1° 19:00	10.3	31%	52.5°
2044-10-27 Thu	81	—	unknown	19:55–00:05 (good, 4.17 h)	71.1° 18:55	10.34	40%	47.8°
2044-10-28 Fri	64	—	unknown	19:55–23:40 (good, 3.75 h)	71.1° 18:55	10.38	49%	45.1°
2044-10-29 Sat	52	—	unknown	19:55–23:25 (good, 3.5 h)	71.1° 18:50	10.41	59%	44.8°
2044-10-30 Sun	43	—	unknown	18:55–20:35 (good, 1.67 h)	71.1° 17:45	10.45	68%	47.0°
2044-10-31 Mon	37	—	unknown	18:55–19:15 (good, 0.33 h)	71.1° 17:40	10.49	77%	51.5°
2044-11-01 Tue	34	—	unknown	18:50–22:55 (marginal, 4.08 h)	71.1° 17:35	10.52	85%	57.9°
2044-11-02 Wed	35	—	unknown	18:50–19:05 (good, 0.25 h)	71.1° 17:35	10.56	92%	65.8°
2044-11-03 Thu	38	—	unknown	18:50–19:45 (good, 0.92 h)	71.1° 17:30	10.6	97%	74.8°
2044-11-04 Fri	45	—	unknown	18:50–20:30 (good, 1.67 h)	71.1° 17:25	10.63	99%	84.6°
2044-11-05 Sat	55	—	unknown	18:45–21:20 (good, 2.58 h)	71.1° 17:20	10.66	100%	94.7°
2044-11-06 Sun	65	—	unknown	18:45–22:00 (good, 3.25 h)	71.1° 17:20	10.7	97%	104.9°
2044-11-07 Mon	74	—	unknown	18:45–22:05 (good, 3.33 h)	71.1° 17:15	10.73	92%	114.6°
2044-11-08 Tue	87	—	unknown	18:45–22:10 (good, 3.42 h)	71.1° 17:10	10.76	84%	123.3°
2044-11-09 Wed	89	—	unknown	18:45–22:05 (good, 3.33 h)	71.1° 17:05	10.8	75%	130.2°
2044-11-10 Thu	89	—	unknown	18:45–22:05 (good, 3.33 h)	71.1° 17:00	10.83	65%	134.5°
2044-11-11 Fri	89	—	unknown	18:40–22:05 (good, 3.42 h)	71.1° 17:00	10.86	53%	135.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-10-13&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.