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 V1057 Cyg: 11-27 (100), 11-28 (100), 11-29 (100), 11-30 (100), 12-01 (100) — by astronomy; check the weather when the night is within four days.

2045-11-21astronomy score per night — click a bar for that night2045-12-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-11-21 Tue	41	—	unknown	18:35–23:45 (marginal, 5.17 h)	87.2° 17:15	11.13	93%	65.2°
2045-11-22 Wed	44	—	unknown	18:35–19:00 (good, 0.42 h)	87.2° 17:15	11.15	97%	71.1°
2045-11-23 Thu	51	—	unknown	18:35–20:10 (good, 1.58 h)	87.3° 17:10	11.18	99%	78.0°
2045-11-24 Fri	61	—	unknown	18:35–21:05 (good, 2.5 h)	87.3° 17:05	11.2	100%	85.6°
2045-11-25 Sat	74	—	unknown	18:35–22:00 (good, 3.42 h)	87.2° 17:00	11.22	97%	93.4°
2045-11-26 Sun	86	—	unknown	18:35–22:50 (good, 4.25 h)	87.2° 17:00	11.24	93%	101.3°
2045-11-27 Mon	100	—	unknown	18:35–22:55 (good, 4.33 h)	87.2° 16:55	11.26	86%	108.7°
2045-11-28 Tue	100	—	unknown	18:35–23:00 (good, 4.42 h)	87.3° 16:50	11.28	77%	115.2°
2045-11-29 Wed	100	—	unknown	18:35–23:00 (good, 4.42 h)	87.2° 16:45	11.3	67%	120.4°
2045-11-30 Thu	100	—	unknown	18:35–23:00 (good, 4.42 h)	87.2° 16:40	11.32	56%	123.8°
2045-12-01 Fri	100	—	unknown	18:35–23:00 (good, 4.42 h)	87.2° 16:40	11.34	44%	124.9°
2045-12-02 Sat	100	—	unknown	18:35–22:55 (good, 4.33 h)	87.3° 16:35	11.35	33%	123.6°
2045-12-03 Sun	100	—	unknown	18:35–22:50 (good, 4.25 h)	87.3° 16:30	11.37	23%	120.1°
2045-12-04 Mon	100	—	unknown	18:35–22:45 (good, 4.17 h)	87.2° 16:25	11.39	14%	114.9°
2045-12-05 Tue	100	—	unknown	18:35–22:40 (good, 4.08 h)	87.2° 16:20	11.4	8%	108.5°
2045-12-06 Wed	100	—	unknown	18:35–22:40 (good, 4.08 h)	87.2° 16:20	11.41	3%	101.4°
2045-12-07 Thu	100	—	unknown	18:35–22:35 (good, 4.0 h)	87.3° 16:15	11.43	0%	93.9°
2045-12-08 Fri	100	—	unknown	18:35–22:30 (good, 3.92 h)	87.3° 16:10	11.44	0%	86.5°
2045-12-09 Sat	100	—	unknown	18:35–22:25 (good, 3.83 h)	87.2° 16:05	11.45	2%	79.3°
2045-12-10 Sun	100	—	unknown	18:35–22:25 (good, 3.83 h)	87.2° 16:05	11.46	6%	72.6°
2045-12-11 Mon	94	—	unknown	18:35–22:20 (good, 3.75 h)	87.2° 16:00	11.47	12%	66.6°
2045-12-12 Tue	87	—	unknown	18:35–22:15 (good, 3.67 h)	87.3° 15:55	11.47	18%	61.7°
2045-12-13 Wed	77	—	unknown	18:35–22:10 (good, 3.58 h)	87.2° 15:50	11.48	26%	57.9°
2045-12-14 Thu	66	—	unknown	18:35–21:55 (good, 3.33 h)	87.2° 15:45	11.49	35%	55.7°
2045-12-15 Fri	56	—	unknown	18:35–21:40 (good, 3.08 h)	87.2° 15:45	11.49	44%	55.0°
2045-12-16 Sat	46	—	unknown	18:35–21:20 (good, 2.75 h)	87.3° 15:40	11.5	54%	56.1°
2045-12-17 Sun	38	—	unknown	18:35–19:40 (good, 1.08 h)	87.3° 15:35	11.5	63%	58.8°
2045-12-18 Mon	33	—	unknown	18:35–18:50 (good, 0.25 h)	87.2° 15:30	11.5	72%	63.0°
2045-12-19 Tue	30	—	unknown	18:00–22:05 (marginal, 4.08 h)	87.2° 15:25	11.51	81%	68.6°
2045-12-20 Wed	31	—	unknown	18:35–18:40 (good, 0.08 h)	87.2° 15:25	11.51	88%	75.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-11-21&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.