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: 09-26 (100), 09-27 (100), 09-28 (100), 09-29 (100), 09-30 (100) — by astronomy; check the weather when the night is within four days.

2029-09-16astronomy score per night — click a bar for that night2029-10-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-09-16 Sun	99	—	unknown	21:05–04:55 (good, 7.83 h)	87.3° 22:35	8.44	70%	69.3°
2029-09-17 Mon	91	—	unknown	21:05–04:55 (good, 7.83 h)	87.3° 22:35	8.49	79%	62.9°
2029-09-18 Tue	83	—	unknown	23:15–04:50 (good, 5.58 h)	87.3° 22:30	8.54	86%	57.8°
2029-09-19 Wed	58	—	unknown	21:00–05:20 (marginal, 8.33 h)	87.3° 22:25	8.59	93%	54.4°
2029-09-20 Thu	54	—	unknown	21:00–05:05 (marginal, 8.08 h)	87.3° 22:20	8.65	97%	52.8°
2029-09-21 Fri	53	—	unknown	20:55–04:50 (marginal, 7.92 h)	87.3° 22:15	8.7	99%	53.3°
2029-09-22 Sat	55	—	unknown	20:55–04:35 (marginal, 7.67 h)	87.3° 22:15	8.75	100%	55.6°
2029-09-23 Sun	63	—	unknown	20:50–21:20 (good, 0.5 h)	87.3° 22:10	8.8	98%	59.5°
2029-09-24 Mon	68	—	unknown	20:50–22:35 (good, 1.75 h)	87.3° 22:05	8.85	95%	64.6°
2029-09-25 Tue	74	—	unknown	20:50–00:35 (good, 3.75 h)	87.3° 22:00	8.9	91%	70.6°
2029-09-26 Wed	100	—	unknown	20:45–01:45 (good, 5.0 h)	87.3° 22:00	8.95	84%	77.2°
2029-09-27 Thu	100	—	unknown	20:45–02:55 (good, 6.17 h)	87.3° 21:55	9.0	77%	84.2°
2029-09-28 Fri	100	—	unknown	20:45–03:40 (good, 6.92 h)	87.3° 21:50	9.05	69%	91.5°
2029-09-29 Sat	100	—	unknown	20:40–03:45 (good, 7.08 h)	87.3° 21:45	9.1	59%	98.8°
2029-09-30 Sun	100	—	unknown	20:40–03:50 (good, 7.17 h)	87.3° 21:40	9.14	50%	105.9°
2029-10-01 Mon	100	—	unknown	20:35–03:50 (good, 7.25 h)	87.3° 21:40	9.19	39%	112.8°
2029-10-02 Tue	100	—	unknown	20:35–03:50 (good, 7.25 h)	87.3° 21:35	9.24	29%	118.9°
2029-10-03 Wed	100	—	unknown	20:35–03:50 (good, 7.25 h)	87.3° 21:30	9.29	20%	123.8°
2029-10-04 Thu	100	—	unknown	20:30–03:45 (good, 7.25 h)	87.3° 21:25	9.34	12%	126.7°
2029-10-05 Fri	100	—	unknown	20:30–03:40 (good, 7.17 h)	87.3° 21:20	9.38	5%	127.2°
2029-10-06 Sat	100	—	unknown	20:30–03:40 (good, 7.17 h)	87.3° 21:20	9.43	1%	124.8°
2029-10-07 Sun	100	—	unknown	20:25–03:35 (good, 7.17 h)	87.3° 21:15	9.48	0%	119.8°
2029-10-08 Mon	100	—	unknown	20:25–03:30 (good, 7.08 h)	87.3° 21:10	9.52	2%	112.9°
2029-10-09 Tue	100	—	unknown	20:25–03:25 (good, 7.0 h)	87.3° 21:05	9.57	7%	104.7°
2029-10-10 Wed	100	—	unknown	20:20–03:20 (good, 7.0 h)	87.3° 21:05	9.61	14%	95.9°
2029-10-11 Thu	100	—	unknown	20:20–03:20 (good, 7.0 h)	87.3° 21:00	9.66	23%	87.1°
2029-10-12 Fri	100	—	unknown	20:20–03:15 (good, 6.92 h)	87.3° 20:55	9.7	33%	78.6°
2029-10-13 Sat	100	—	unknown	20:20–03:10 (good, 6.83 h)	87.3° 20:50	9.75	44%	70.9°
2029-10-14 Sun	93	—	unknown	20:15–03:05 (good, 6.83 h)	87.3° 20:45	9.79	55%	64.1°
2029-10-15 Mon	86	—	unknown	20:15–03:05 (good, 6.83 h)	87.3° 20:45	9.83	65%	58.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-09-16&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.