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: 12-05 (100), 12-06 (100), 12-07 (100), 12-08 (100), 12-09 (100) — by astronomy; check the weather when the night is within four days.

2028-12-03astronomy score per night — click a bar for that night2029-01-01

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-12-03 Sun	77	—	unknown	18:35–22:20 (good, 3.75 h)	87.3° 16:30	11.37	96%	102.5°
2028-12-04 Mon	98	—	unknown	18:35–22:25 (good, 3.83 h)	87.3° 16:25	11.39	91%	110.0°
2028-12-05 Tue	100	—	unknown	18:35–22:30 (good, 3.92 h)	87.3° 16:20	11.4	84%	116.6°
2028-12-06 Wed	100	—	unknown	18:35–22:30 (good, 3.92 h)	87.3° 16:15	11.41	75%	122.1°
2028-12-07 Thu	100	—	unknown	18:35–22:35 (good, 4.0 h)	87.3° 16:15	11.43	65%	125.7°
2028-12-08 Fri	100	—	unknown	18:35–22:30 (good, 3.92 h)	87.3° 16:10	11.44	54%	127.0°
2028-12-09 Sat	100	—	unknown	18:35–22:25 (good, 3.83 h)	87.3° 16:05	11.45	42%	125.7°
2028-12-10 Sun	99	—	unknown	18:35–22:20 (good, 3.75 h)	87.3° 16:00	11.46	31%	122.0°
2028-12-11 Mon	97	—	unknown	18:35–22:15 (good, 3.67 h)	87.3° 16:00	11.47	21%	116.3°
2028-12-12 Tue	96	—	unknown	18:35–22:15 (good, 3.67 h)	87.3° 15:55	11.48	12%	109.2°
2028-12-13 Wed	94	—	unknown	18:35–22:10 (good, 3.58 h)	87.3° 15:50	11.48	6%	101.3°
2028-12-14 Thu	92	—	unknown	18:35–22:05 (good, 3.5 h)	87.3° 15:45	11.49	2%	93.0°
2028-12-15 Fri	90	—	unknown	18:35–22:00 (good, 3.42 h)	87.3° 15:40	11.49	0%	84.7°
2028-12-16 Sat	89	—	unknown	18:35–22:00 (good, 3.42 h)	87.3° 15:40	11.5	1%	76.7°
2028-12-17 Sun	86	—	unknown	18:35–21:55 (good, 3.33 h)	87.3° 15:35	11.5	4%	69.4°
2028-12-18 Mon	81	—	unknown	18:35–21:50 (good, 3.25 h)	87.3° 15:30	11.51	9%	63.1°
2028-12-19 Tue	75	—	unknown	18:35–21:45 (good, 3.17 h)	87.3° 15:25	11.51	15%	58.1°
2028-12-20 Wed	65	—	unknown	18:35–21:40 (good, 3.08 h)	87.3° 15:20	11.51	23%	54.7°
2028-12-21 Thu	56	—	unknown	18:35–21:25 (good, 2.83 h)	87.3° 15:20	11.51	32%	53.1°
2028-12-22 Fri	47	—	unknown	18:35–21:10 (good, 2.58 h)	87.3° 15:15	11.51	41%	53.4°
2028-12-23 Sat	39	—	unknown	18:40–20:55 (good, 2.25 h)	87.3° 15:10	11.5	50%	55.4°
2028-12-24 Sun	32	—	unknown	18:40–19:30 (good, 0.83 h)	87.3° 15:05	11.5	60%	59.0°
2028-12-25 Mon	28	—	unknown	18:40–18:45 (good, 0.08 h)	87.3° 15:05	11.5	69%	64.0°
2028-12-26 Tue	26	—	unknown	18:40–21:40 (marginal, 3.0 h)	87.3° 15:00	11.49	77%	70.0°
2028-12-27 Wed	26	—	unknown	18:40–21:35 (marginal, 2.92 h)	87.3° 14:55	11.49	85%	76.8°
2028-12-28 Thu	28	—	unknown	18:40–19:00 (good, 0.33 h)	87.3° 14:50	11.48	92%	84.2°
2028-12-29 Fri	30	—	unknown	18:40–19:35 (good, 0.92 h)	87.3° 14:45	11.47	96%	92.0°
2028-12-30 Sat	35	—	unknown	18:40–20:20 (good, 1.67 h)	87.3° 14:45	11.47	99%	99.9°
2028-12-31 Sun	38	—	unknown	18:45–20:35 (good, 1.83 h)	87.3° 14:40	11.46	100%	107.6°
2029-01-01 Mon	43	—	unknown	18:45–20:40 (good, 1.92 h)	87.3° 14:35	11.45	98%	114.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-12-03&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.