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: 04-18 (59), 04-17 (55), 04-04 (54), 04-02 (53), 04-03 (53) — by astronomy; check the weather when the night is within four days.

2047-03-20astronomy score per night — click a bar for that night2047-04-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-03-20 Wed	37	—	unknown	03:10–04:50 (good, 1.67 h)	87.2° 09:25	8.73	27%	66.0°
2047-03-21 Thu	40	—	unknown	03:10–04:50 (good, 1.67 h)	87.2° 09:25	8.67	18%	60.5°
2047-03-22 Fri	43	—	unknown	03:05–04:50 (good, 1.75 h)	87.2° 09:20	8.62	12%	56.5°
2047-03-23 Sat	44	—	unknown	03:00–04:45 (good, 1.75 h)	87.2° 09:15	8.57	6%	54.2°
2047-03-24 Sun	46	—	unknown	02:55–04:45 (good, 1.83 h)	87.2° 09:10	8.52	2%	53.7°
2047-03-25 Mon	47	—	unknown	02:50–04:45 (good, 1.92 h)	87.2° 09:05	8.46	0%	55.0°
2047-03-26 Tue	47	—	unknown	02:50–04:40 (good, 1.83 h)	87.2° 09:05	8.41	0%	58.1°
2047-03-27 Wed	48	—	unknown	02:45–04:40 (good, 1.92 h)	87.2° 09:00	8.36	2%	62.5°
2047-03-28 Thu	48	—	unknown	02:40–04:35 (good, 1.92 h)	87.2° 08:55	8.3	6%	67.9°
2047-03-29 Fri	50	—	unknown	02:35–04:35 (good, 2.0 h)	87.2° 08:50	8.25	10%	74.1°
2047-03-30 Sat	51	—	unknown	02:30–05:35 (good, 2.08 h)	87.2° 09:45	8.2	17%	80.8°
2047-03-31 Sun	51	—	unknown	03:30–05:30 (good, 2.0 h)	87.2° 09:45	8.14	25%	87.8°
2047-04-01 Mon	52	—	unknown	03:25–05:30 (good, 2.08 h)	87.2° 09:40	8.09	33%	95.0°
2047-04-02 Tue	53	—	unknown	03:20–05:30 (good, 2.17 h)	87.2° 09:35	8.03	43%	102.2°
2047-04-03 Wed	53	—	unknown	03:15–05:25 (good, 2.17 h)	87.2° 09:30	7.98	53%	109.1°
2047-04-04 Thu	54	—	unknown	03:20–05:25 (good, 2.08 h)	87.2° 09:30	7.92	63%	115.6°
2047-04-05 Fri	53	—	unknown	03:15–05:20 (good, 2.08 h)	87.2° 09:25	7.87	74%	121.0°
2047-04-06 Sat	53	—	unknown	03:15–05:20 (good, 2.08 h)	87.2° 09:20	7.81	83%	124.9°
2047-04-07 Sun	50	—	unknown	03:10–05:20 (good, 2.17 h)	87.2° 09:15	7.75	91%	126.5°
2047-04-08 Mon	48	—	unknown	03:10–05:15 (good, 2.08 h)	87.2° 09:10	7.7	96%	125.3°
2047-04-09 Tue	48	—	unknown	03:05–05:15 (good, 2.17 h)	87.2° 09:10	7.64	99%	121.4°
2047-04-10 Wed	45	—	unknown	03:05–05:10 (good, 2.08 h)	87.2° 09:05	7.58	99%	115.3°
2047-04-11 Thu	43	—	unknown	03:05–05:10 (good, 2.08 h)	87.2° 09:00	7.53	96%	107.7°
2047-04-12 Fri	41	—	unknown	03:05–05:10 (good, 2.08 h)	87.2° 08:55	7.47	91%	99.3°
2047-04-13 Sat	39	—	unknown	03:00–05:05 (good, 2.08 h)	87.2° 08:50	7.41	83%	90.6°
2047-04-14 Sun	40	—	unknown	02:55–05:05 (good, 2.17 h)	87.2° 08:50	7.36	73%	82.2°
2047-04-15 Mon	42	—	unknown	02:50–05:00 (good, 2.17 h)	87.2° 08:45	7.3	63%	74.3°
2047-04-16 Tue	46	—	unknown	02:25–05:00 (good, 2.58 h)	87.2° 08:40	7.24	52%	67.4°
2047-04-17 Wed	55	—	unknown	02:20–05:00 (good, 2.67 h)	87.2° 08:35	7.18	42%	61.5°
2047-04-18 Thu	59	—	unknown	02:20–04:55 (good, 2.58 h)	87.2° 08:35	7.12	32%	57.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-03-20&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.