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.

2034-05-04astronomy score per night — click a bar for that night2034-06-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-05-04 Thu	46	—	unknown	02:10–04:25 (good, 2.25 h)	87.3° 07:30	6.19	98%	91.4°
2034-05-05 Fri	44	—	unknown	02:25–04:25 (good, 2.0 h)	87.3° 07:25	6.13	95%	84.6°
2034-05-06 Sat	42	—	unknown	02:25–04:20 (good, 1.92 h)	87.3° 07:20	6.07	90%	77.9°
2034-05-07 Sun	43	—	unknown	02:00–04:20 (good, 2.33 h)	87.3° 07:15	6.02	83%	71.6°
2034-05-08 Mon	46	—	unknown	01:30–04:20 (good, 2.83 h)	87.3° 07:15	5.96	75%	65.8°
2034-05-09 Tue	56	—	unknown	00:55–04:15 (good, 3.33 h)	87.3° 07:10	5.9	66%	60.8°
2034-05-10 Wed	67	—	unknown	00:50–04:15 (good, 3.42 h)	87.3° 07:05	5.85	56%	57.2°
2034-05-11 Thu	76	—	unknown	00:45–04:15 (good, 3.5 h)	87.3° 07:00	5.79	45%	55.3°
2034-05-12 Fri	84	—	unknown	00:40–04:10 (good, 3.5 h)	87.3° 06:55	5.74	34%	55.6°
2034-05-13 Sat	91	—	unknown	00:40–04:10 (good, 3.5 h)	87.3° 06:55	5.68	24%	58.1°
2034-05-14 Sun	96	—	unknown	00:35–04:10 (good, 3.58 h)	87.3° 06:50	5.63	15%	62.7°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-05-04&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.