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: 10-29 (100), 10-30 (100), 10-31 (100), 11-01 (100), 11-02 (100) — by astronomy; check the weather when the night is within four days.

2045-10-24astronomy score per night — click a bar for that night2045-11-22

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-10-24 Tue	50	—	unknown	20:00–02:30 (marginal, 6.5 h)	87.2° 20:10	10.21	99%	62.0°
2045-10-25 Wed	56	—	unknown	20:00–20:40 (good, 0.67 h)	87.2° 20:05	10.25	100%	67.2°
2045-10-26 Thu	66	—	unknown	20:00–22:10 (good, 2.17 h)	87.3° 20:00	10.29	99%	73.4°
2045-10-27 Fri	75	—	unknown	20:00–23:30 (good, 3.5 h)	87.3° 19:55	10.33	95%	80.4°
2045-10-28 Sat	82	—	unknown	19:55–00:35 (good, 4.67 h)	87.2° 19:50	10.37	90%	87.9°
2045-10-29 Sun	100	—	unknown	18:55–00:35 (good, 5.67 h)	87.2° 18:50	10.41	82%	95.5°
2045-10-30 Mon	100	—	unknown	18:55–00:45 (good, 5.83 h)	87.2° 18:45	10.44	73%	103.1°
2045-10-31 Tue	100	—	unknown	18:55–00:50 (good, 5.92 h)	87.3° 18:40	10.48	63%	110.1°
2045-11-01 Wed	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.2° 18:35	10.52	52%	116.3°
2045-11-02 Thu	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.2° 18:30	10.55	41%	121.1°
2045-11-03 Fri	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.2° 18:30	10.59	30%	124.0°
2045-11-04 Sat	100	—	unknown	18:50–00:45 (good, 5.92 h)	87.3° 18:25	10.62	20%	124.5°
2045-11-05 Sun	100	—	unknown	18:50–00:40 (good, 5.83 h)	87.3° 18:20	10.66	11%	122.6°
2045-11-06 Mon	100	—	unknown	18:45–00:35 (good, 5.83 h)	87.2° 18:15	10.69	5%	118.6°
2045-11-07 Tue	100	—	unknown	18:45–00:35 (good, 5.83 h)	87.2° 18:15	10.72	1%	112.9°
2045-11-08 Wed	100	—	unknown	18:45–00:30 (good, 5.75 h)	87.2° 18:10	10.76	0%	106.1°
2045-11-09 Thu	100	—	unknown	18:45–00:25 (good, 5.67 h)	87.3° 18:05	10.79	1%	98.8°
2045-11-10 Fri	100	—	unknown	18:45–00:20 (good, 5.58 h)	87.3° 18:00	10.82	5%	91.3°
2045-11-11 Sat	100	—	unknown	18:40–00:15 (good, 5.58 h)	87.2° 17:55	10.85	10%	83.9°
2045-11-12 Sun	100	—	unknown	18:40–00:15 (good, 5.58 h)	87.2° 17:55	10.88	17%	76.9°
2045-11-13 Mon	99	—	unknown	18:40–00:10 (good, 5.5 h)	87.2° 17:50	10.91	25%	70.5°
2045-11-14 Tue	91	—	unknown	18:40–00:05 (good, 5.42 h)	87.3° 17:45	10.94	34%	65.0°
2045-11-15 Wed	84	—	unknown	18:40–00:00 (good, 5.33 h)	87.2° 17:40	10.97	43%	60.5°
2045-11-16 Thu	76	—	unknown	18:40–23:35 (good, 4.92 h)	87.2° 17:35	11.0	53%	57.2°
2045-11-17 Fri	67	—	unknown	18:40–23:20 (good, 4.67 h)	87.2° 17:35	11.03	62%	55.5°
2045-11-18 Sat	55	—	unknown	18:35–20:55 (good, 2.33 h)	87.3° 17:30	11.05	71%	55.4°
2045-11-19 Sun	46	—	unknown	18:35–00:10 (marginal, 5.58 h)	87.3° 17:25	11.08	79%	57.1°
2045-11-20 Mon	42	—	unknown	18:35–23:55 (marginal, 5.33 h)	87.2° 17:20	11.1	86%	60.4°
2045-11-21 Tue	41	—	unknown	18:35–23:45 (marginal, 5.17 h)	87.2° 17:15	11.13	93%	65.2°
2045-11-22 Wed	44	—	unknown	18:35–19:00 (good, 0.42 h)	87.2° 17:15	11.15	97%	71.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-10-24&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.