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 North America Nebula: 12-01 (100), 12-02 (100), 12-03 (100), 12-04 (100), 12-05 (100) — by astronomy; check the weather when the night is within four days.

2031-11-19astronomy score per night — click a bar for that night2031-12-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-11-19 Wed	89	—	unknown	18:35–23:45 (good, 5.17 h)	87.2° 17:25	11.06	31%	58.9°
2031-11-20 Thu	81	—	unknown	18:35–23:45 (good, 5.17 h)	87.2° 17:25	11.09	42%	54.6°
2031-11-21 Fri	72	—	unknown	18:35–23:15 (good, 4.67 h)	87.2° 17:20	11.11	54%	52.6°
2031-11-22 Sat	57	—	unknown	18:35–21:40 (good, 3.08 h)	87.2° 17:15	11.14	64%	53.2°
2031-11-23 Sun	47	—	unknown	18:35–19:00 (good, 0.42 h)	87.2° 17:10	11.16	75%	56.2°
2031-11-24 Mon	43	—	unknown	18:35–23:45 (marginal, 5.17 h)	87.2° 17:05	11.19	83%	61.0°
2031-11-25 Tue	43	—	unknown	18:35–18:40 (good, 0.08 h)	87.2° 17:05	11.21	90%	67.2°
2031-11-26 Wed	46	—	unknown	18:35–19:45 (good, 1.17 h)	87.2° 17:00	11.23	96%	74.3°
2031-11-27 Thu	53	—	unknown	18:35–20:25 (good, 1.83 h)	87.2° 16:55	11.25	99%	81.7°
2031-11-28 Fri	62	—	unknown	18:35–21:15 (good, 2.67 h)	87.2° 16:50	11.27	100%	89.4°
2031-11-29 Sat	73	—	unknown	18:35–22:05 (good, 3.5 h)	87.2° 16:50	11.29	99%	96.9°
2031-11-30 Sun	84	—	unknown	18:35–22:35 (good, 4.0 h)	87.2° 16:45	11.31	96%	104.1°
2031-12-01 Mon	100	—	unknown	18:35–22:40 (good, 4.08 h)	87.2° 16:40	11.33	92%	110.8°
2031-12-02 Tue	100	—	unknown	18:35–22:45 (good, 4.17 h)	87.2° 16:35	11.34	86%	116.7°
2031-12-03 Wed	100	—	unknown	18:35–22:45 (good, 4.17 h)	87.2° 16:30	11.36	79%	121.6°
2031-12-04 Thu	100	—	unknown	18:35–22:40 (good, 4.08 h)	87.2° 16:30	11.38	70%	125.2°
2031-12-05 Fri	100	—	unknown	18:35–22:45 (good, 4.17 h)	87.2° 16:25	11.39	62%	127.1°
2031-12-06 Sat	100	—	unknown	18:35–22:40 (good, 4.08 h)	87.2° 16:20	11.4	52%	127.3°
2031-12-07 Sun	100	—	unknown	18:35–22:35 (good, 4.0 h)	87.2° 16:15	11.42	42%	125.5°
2031-12-08 Mon	100	—	unknown	18:35–22:30 (good, 3.92 h)	87.2° 16:10	11.43	33%	121.8°
2031-12-09 Tue	100	—	unknown	18:35–22:30 (good, 3.92 h)	87.2° 16:10	11.44	23%	116.5°
2031-12-10 Wed	100	—	unknown	18:35–22:25 (good, 3.83 h)	87.2° 16:05	11.45	15%	109.8°
2031-12-11 Thu	99	—	unknown	18:35–22:20 (good, 3.75 h)	87.2° 16:00	11.46	8%	102.1°
2031-12-12 Fri	97	—	unknown	18:35–22:15 (good, 3.67 h)	87.2° 15:55	11.47	3%	93.6°
2031-12-13 Sat	96	—	unknown	18:35–22:15 (good, 3.67 h)	87.2° 15:55	11.48	0%	84.8°
2031-12-14 Sun	94	—	unknown	18:35–22:10 (good, 3.58 h)	87.2° 15:50	11.48	0%	76.0°
2031-12-15 Mon	92	—	unknown	18:35–22:05 (good, 3.5 h)	87.2° 15:45	11.49	4%	67.8°
2031-12-16 Tue	86	—	unknown	18:35–22:00 (good, 3.42 h)	87.2° 15:40	11.5	10%	60.8°
2031-12-17 Wed	78	—	unknown	18:35–21:55 (good, 3.33 h)	87.2° 15:35	11.5	18%	55.7°
2031-12-18 Thu	67	—	unknown	18:35–21:45 (good, 3.17 h)	87.2° 15:35	11.5	27%	53.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-11-19&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.