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: 12-09 (100), 12-10 (99), 12-11 (98), 12-12 (96), 12-13 (94) — by astronomy; check the weather when the night is within four days.

2036-12-09astronomy score per night — click a bar for that night2037-01-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-12-09 Tue	100	—	unknown	18:35–22:25 (good, 3.83 h)	87.3° 16:05	11.45	55%	119.7°
2036-12-10 Wed	99	—	unknown	18:35–22:20 (good, 3.75 h)	87.3° 16:00	11.46	44%	117.3°
2036-12-11 Thu	98	—	unknown	18:35–22:20 (good, 3.75 h)	87.3° 16:00	11.47	33%	113.2°
2036-12-12 Fri	96	—	unknown	18:35–22:15 (good, 3.67 h)	87.3° 15:55	11.48	23%	108.0°
2036-12-13 Sat	94	—	unknown	18:35–22:10 (good, 3.58 h)	87.3° 15:50	11.48	15%	102.0°
2036-12-14 Sun	92	—	unknown	18:35–22:05 (good, 3.5 h)	87.3° 15:45	11.49	8%	95.5°
2036-12-15 Mon	90	—	unknown	18:35–22:00 (good, 3.42 h)	87.3° 15:40	11.49	3%	88.9°
2036-12-16 Tue	89	—	unknown	18:35–22:00 (good, 3.42 h)	87.3° 15:40	11.5	1%	82.5°
2036-12-17 Wed	86	—	unknown	18:35–21:55 (good, 3.33 h)	87.3° 15:35	11.5	0%	76.4°
2036-12-18 Thu	84	—	unknown	18:35–21:50 (good, 3.25 h)	87.3° 15:30	11.5	2%	71.0°
2036-12-19 Fri	81	—	unknown	18:35–21:45 (good, 3.17 h)	87.3° 15:25	11.51	5%	66.4°
2036-12-20 Sat	76	—	unknown	18:35–21:40 (good, 3.08 h)	87.3° 15:20	11.51	10%	62.9°
2036-12-21 Sun	70	—	unknown	18:35–21:40 (good, 3.08 h)	87.3° 15:20	11.51	16%	60.7°
2036-12-22 Mon	63	—	unknown	18:35–21:35 (good, 3.0 h)	87.3° 15:15	11.51	24%	59.8°
2036-12-23 Tue	54	—	unknown	18:40–21:20 (good, 2.67 h)	87.3° 15:10	11.5	32%	60.4°
2036-12-24 Wed	47	—	unknown	18:40–21:05 (good, 2.42 h)	87.3° 15:05	11.5	42%	62.3°
2036-12-25 Thu	41	—	unknown	18:40–20:55 (good, 2.25 h)	87.3° 15:05	11.5	51%	65.4°
2036-12-26 Fri	35	—	unknown	18:40–20:25 (good, 1.75 h)	87.3° 15:00	11.49	61%	69.7°
2036-12-27 Sat	32	—	unknown	18:40–19:45 (good, 1.08 h)	87.3° 14:55	11.49	70%	75.0°
2036-12-28 Sun	30	—	unknown	18:40–19:25 (good, 0.75 h)	87.3° 14:50	11.48	79%	81.0°
2036-12-29 Mon	30	—	unknown	18:40–19:35 (good, 0.92 h)	87.3° 14:45	11.47	87%	87.6°
2036-12-30 Tue	32	—	unknown	18:40–19:55 (good, 1.25 h)	87.3° 14:45	11.47	94%	94.4°
2036-12-31 Wed	34	—	unknown	18:45–20:25 (good, 1.67 h)	87.3° 14:40	11.46	98%	101.3°
2037-01-01 Thu	37	—	unknown	18:45–20:30 (good, 1.75 h)	87.3° 14:35	11.45	100%	107.9°
2037-01-02 Fri	40	—	unknown	18:45–20:35 (good, 1.83 h)	87.3° 14:30	11.44	99%	113.5°
2037-01-03 Sat	47	—	unknown	18:45–20:35 (good, 1.83 h)	87.3° 14:25	11.42	95%	117.6°
2037-01-04 Sun	48	—	unknown	18:45–20:35 (good, 1.83 h)	87.3° 14:25	11.41	89%	119.9°
2037-01-05 Mon	47	—	unknown	18:45–20:40 (good, 1.92 h)	87.3° 14:20	11.4	80%	119.9°
2037-01-06 Tue	44	—	unknown	18:50–20:35 (good, 1.75 h)	87.3° 14:15	11.38	70%	117.9°
2037-01-07 Wed	43	—	unknown	18:50–20:30 (good, 1.67 h)	87.3° 14:10	11.37	59%	114.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-12-09&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.