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: 10-25 (100), 10-26 (93), 11-09 (89), 11-10 (89), 11-11 (89) — by astronomy; check the weather when the night is within four days.

2044-10-25astronomy score per night — click a bar for that night2044-11-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2044-11-12 Sat	88	—	unknown	18:40–22:00 (good, 3.33 h)	71.1° 16:55	10.89	42%	132.9°
2044-11-13 Sun	86	—	unknown	18:40–21:55 (good, 3.25 h)	71.1° 16:50	10.92	32%	127.7°
2044-11-14 Mon	85	—	unknown	18:40–21:55 (good, 3.25 h)	71.1° 16:45	10.95	22%	120.6°
2044-11-15 Tue	83	—	unknown	18:40–21:50 (good, 3.17 h)	71.1° 16:40	10.98	14%	112.4°
2044-11-16 Wed	81	—	unknown	18:40–21:45 (good, 3.08 h)	71.1° 16:40	11.01	8%	103.6°
2044-11-17 Thu	79	—	unknown	18:40–21:40 (good, 3.0 h)	71.1° 16:35	11.03	3%	94.6°
2044-11-18 Fri	79	—	unknown	18:35–21:35 (good, 3.0 h)	71.1° 16:30	11.06	1%	85.5°
2044-11-19 Sat	77	—	unknown	18:35–21:35 (good, 3.0 h)	71.1° 16:25	11.09	0%	76.8°
2044-11-20 Sun	75	—	unknown	18:35–21:30 (good, 2.92 h)	71.1° 16:25	11.11	2%	68.4°
2044-11-21 Mon	72	—	unknown	18:35–21:25 (good, 2.83 h)	71.1° 16:20	11.14	5%	60.8°
2044-11-22 Tue	71	—	unknown	18:35–21:20 (good, 2.75 h)	71.1° 16:15	11.16	10%	54.2°
2044-11-23 Wed	64	—	unknown	18:35–21:15 (good, 2.67 h)	71.1° 16:10	11.18	16%	48.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-10-25&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.