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: 06-27 (100), 06-28 (100), 06-29 (100), 06-30 (100), 07-01 (100) — by astronomy; check the weather when the night is within four days.

2046-06-16astronomy score per night — click a bar for that night2046-07-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-06-16 Sat	83	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:40	4.44	97%	95.8°
2046-06-17 Sun	74	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:35	4.43	99%	87.9°
2046-06-18 Mon	65	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:30	4.43	100%	80.2°
2046-06-19 Tue	59	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:30	4.42	98%	73.0°
2046-06-20 Wed	57	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:25	4.42	94%	66.5°
2046-06-21 Thu	75	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:20	4.42	88%	61.2°
2046-06-22 Fri	82	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:15	4.43	81%	57.3°
2046-06-23 Sat	90	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:10	4.43	73%	54.9°
2046-06-24 Sun	93	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:10	4.44	64%	54.3°
2046-06-25 Mon	96	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:05	4.45	55%	55.4°
2046-06-26 Tue	99	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:00	4.46	45%	58.1°
2046-06-27 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:55	4.47	36%	62.3°
2046-06-28 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:50	4.48	27%	67.7°
2046-06-29 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 03:50	4.5	19%	74.0°
2046-06-30 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:45	4.52	11%	81.1°
2046-07-01 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:40	4.54	6%	88.6°
2046-07-02 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:35	4.56	2%	96.5°
2046-07-03 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:35	4.59	0%	104.2°
2046-07-04 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:30	4.61	1%	111.5°
2046-07-05 Thu	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.3° 03:25	4.64	4%	117.9°
2046-07-06 Fri	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:20	4.67	11%	122.7°
2046-07-07 Sat	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:15	4.7	19%	125.4°
2046-07-08 Sun	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:15	4.74	29%	125.6°
2046-07-09 Mon	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:10	4.77	40%	123.2°
2046-07-10 Tue	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.3° 03:05	4.81	51%	118.7°
2046-07-11 Wed	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:00	4.84	62%	112.7°
2046-07-12 Thu	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 02:55	4.88	73%	105.6°
2046-07-13 Fri	100	—	unknown	23:00–03:55 (good, 4.92 h)	87.2° 02:55	4.92	82%	98.0°
2046-07-14 Sat	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.3° 02:50	4.96	90%	90.2°
2046-07-15 Sun	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:45	5.01	95%	82.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-06-16&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.