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: 05-17 (100), 05-18 (100), 05-19 (100), 05-20 (100), 05-21 (100) — by astronomy; check the weather when the night is within four days.

2034-05-15astronomy score per night — click a bar for that night2034-06-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-05-15 Mon	97	—	unknown	00:30–04:05 (good, 3.58 h)	87.3° 06:45	5.57	7%	69.2°
2034-05-16 Tue	99	—	unknown	00:25–04:05 (good, 3.67 h)	87.3° 06:40	5.52	2%	76.9°
2034-05-17 Wed	100	—	unknown	00:25–04:05 (good, 3.67 h)	87.3° 06:40	5.47	0%	85.3°
2034-05-18 Thu	100	—	unknown	00:20–04:00 (good, 3.67 h)	87.3° 06:35	5.42	1%	93.9°
2034-05-19 Fri	100	—	unknown	00:15–04:00 (good, 3.75 h)	87.3° 06:30	5.37	5%	102.3°
2034-05-20 Sat	100	—	unknown	00:10–04:00 (good, 3.83 h)	87.3° 06:25	5.32	11%	109.8°
2034-05-21 Sun	100	—	unknown	00:05–04:00 (good, 3.92 h)	87.3° 06:20	5.27	20%	116.2°
2034-05-22 Mon	100	—	unknown	00:05–03:55 (good, 3.83 h)	87.3° 06:20	5.22	29%	120.9°
2034-05-23 Tue	100	—	unknown	00:05–03:55 (good, 3.83 h)	87.3° 06:15	5.17	39%	123.8°
2034-05-24 Wed	100	—	unknown	00:00–03:55 (good, 3.92 h)	87.3° 06:10	5.13	49%	124.7°
2034-05-25 Thu	100	—	unknown	00:00–03:55 (good, 3.92 h)	87.3° 06:05	5.08	59%	123.7°
2034-05-26 Fri	100	—	unknown	23:55–03:50 (good, 3.92 h)	87.3° 06:00	5.04	69%	121.1°
2034-05-27 Sat	100	—	unknown	23:55–03:50 (good, 3.92 h)	87.3° 06:00	4.99	77%	117.0°
2034-05-28 Sun	91	—	unknown	23:55–03:50 (good, 3.92 h)	87.3° 05:55	4.95	85%	111.9°
2034-05-29 Mon	84	—	unknown	00:00–03:50 (good, 3.83 h)	87.3° 05:50	4.91	91%	106.1°
2034-05-30 Tue	75	—	unknown	00:00–03:45 (good, 3.75 h)	87.3° 05:45	4.87	95%	99.8°
2034-05-31 Wed	67	—	unknown	00:15–03:45 (good, 3.5 h)	87.3° 05:45	4.83	98%	93.1°
2034-06-01 Thu	60	—	unknown	00:50–03:45 (good, 2.92 h)	87.3° 05:40	4.79	100%	86.3°
2034-06-02 Fri	55	—	unknown	01:20–03:45 (good, 2.42 h)	87.3° 05:35	4.76	99%	79.6°
2034-06-03 Sat	51	—	unknown	01:40–03:45 (good, 2.08 h)	87.3° 05:30	4.72	97%	73.2°
2034-06-04 Sun	50	—	unknown	01:35–03:45 (good, 2.17 h)	87.3° 05:25	4.69	93%	67.2°
2034-06-05 Mon	57	—	unknown	00:15–03:40 (good, 3.42 h)	87.3° 05:25	4.66	87%	62.1°
2034-06-06 Tue	74	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:20	4.63	79%	58.2°
2034-06-07 Wed	85	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:15	4.61	70%	55.9°
2034-06-08 Thu	91	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:10	4.58	60%	55.5°
2034-06-09 Fri	96	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:05	4.56	49%	57.3°
2034-06-10 Sat	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:05	4.53	38%	61.2°
2034-06-11 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 05:00	4.51	27%	66.9°
2034-06-12 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:55	4.5	17%	73.9°
2034-06-13 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:50	4.48	9%	81.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-05-15&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.