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: 12-07 (100), 12-08 (100), 12-09 (100), 12-10 (100), 12-11 (99) — by astronomy; check the weather when the night is within four days.

2031-12-07astronomy score per night — click a bar for that night2032-01-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-12-07 Sun	100	—	unknown	18:35–22:35 (good, 4.0 h)	87.3° 16:15	11.42	42%	125.5°
2031-12-08 Mon	100	—	unknown	18:35–22:30 (good, 3.92 h)	87.3° 16:15	11.43	33%	121.9°
2031-12-09 Tue	100	—	unknown	18:35–22:30 (good, 3.92 h)	87.3° 16:10	11.44	23%	116.6°
2031-12-10 Wed	100	—	unknown	18:35–22:25 (good, 3.83 h)	87.3° 16:05	11.45	15%	109.9°
2031-12-11 Thu	99	—	unknown	18:35–22:20 (good, 3.75 h)	87.3° 16:00	11.46	8%	102.1°
2031-12-12 Fri	97	—	unknown	18:35–22:15 (good, 3.67 h)	87.3° 15:55	11.47	3%	93.6°
2031-12-13 Sat	96	—	unknown	18:35–22:15 (good, 3.67 h)	87.3° 15:55	11.48	0%	84.8°
2031-12-14 Sun	94	—	unknown	18:35–22:10 (good, 3.58 h)	87.3° 15:50	11.48	0%	76.0°
2031-12-15 Mon	92	—	unknown	18:35–22:05 (good, 3.5 h)	87.3° 15:45	11.49	4%	67.8°
2031-12-16 Tue	86	—	unknown	18:35–22:00 (good, 3.42 h)	87.3° 15:40	11.5	10%	60.8°
2031-12-17 Wed	77	—	unknown	18:35–21:55 (good, 3.33 h)	87.3° 15:35	11.5	18%	55.6°
2031-12-18 Thu	67	—	unknown	18:35–21:45 (good, 3.17 h)	87.3° 15:35	11.5	27%	52.9°
2031-12-19 Fri	55	—	unknown	18:35–21:30 (good, 2.92 h)	87.3° 15:30	11.51	38%	52.9°
2031-12-20 Sat	45	—	unknown	18:35–21:15 (good, 2.67 h)	87.3° 15:25	11.51	49%	55.4°
2031-12-21 Sun	37	—	unknown	18:35–20:00 (good, 1.42 h)	87.3° 15:20	11.51	60%	59.9°
2031-12-22 Mon	32	—	unknown	18:35–19:05 (good, 0.5 h)	87.3° 15:15	11.51	70%	65.8°
2031-12-23 Tue	30	—	unknown	18:40–18:55 (good, 0.25 h)	87.3° 15:15	11.51	79%	72.6°
2031-12-24 Wed	31	—	unknown	18:40–19:05 (good, 0.42 h)	87.3° 15:10	11.5	87%	79.9°
2031-12-25 Thu	33	—	unknown	18:40–19:35 (good, 0.92 h)	87.3° 15:05	11.5	93%	87.4°
2031-12-26 Fri	36	—	unknown	18:40–20:10 (good, 1.5 h)	87.3° 15:00	11.5	97%	94.9°
2031-12-27 Sat	41	—	unknown	18:40–20:45 (good, 2.08 h)	87.3° 15:00	11.49	99%	102.2°
2031-12-28 Sun	45	—	unknown	18:40–20:50 (good, 2.17 h)	87.3° 14:55	11.49	100%	109.0°
2031-12-29 Mon	49	—	unknown	18:40–20:55 (good, 2.25 h)	87.3° 14:50	11.48	98%	115.1°
2031-12-30 Tue	56	—	unknown	18:40–20:55 (good, 2.25 h)	87.3° 14:45	11.47	96%	120.3°
2031-12-31 Wed	55	—	unknown	18:45–20:55 (good, 2.17 h)	87.3° 14:40	11.46	91%	124.2°
2032-01-01 Thu	55	—	unknown	18:45–20:55 (good, 2.17 h)	87.3° 14:40	11.45	85%	126.7°
2032-01-02 Fri	54	—	unknown	18:45–20:55 (good, 2.17 h)	87.3° 14:35	11.44	77%	127.3°
2032-01-03 Sat	52	—	unknown	18:45–20:50 (good, 2.08 h)	87.3° 14:30	11.43	69%	126.1°
2032-01-04 Sun	50	—	unknown	18:45–20:45 (good, 2.0 h)	87.3° 14:25	11.42	60%	123.0°
2032-01-05 Mon	48	—	unknown	18:45–20:40 (good, 1.92 h)	87.3° 14:20	11.41	50%	118.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-12-07&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.