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: 06-29 (100), 06-30 (100), 07-01 (100), 07-02 (100), 07-03 (100) — by astronomy; check the weather when the night is within four days.

2043-06-22astronomy score per night — click a bar for that night2043-07-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-06-22 Mon	68	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:15	4.42	100%	80.8°
2043-06-23 Tue	63	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:15	4.43	98%	74.9°
2043-06-24 Wed	63	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:10	4.43	94%	69.6°
2043-06-25 Thu	83	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:05	4.44	89%	65.0°
2043-06-26 Fri	91	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:00	4.45	82%	61.5°
2043-06-27 Sat	94	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:55	4.47	73%	59.6°
2043-06-28 Sun	97	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:55	4.48	63%	59.3°
2043-06-29 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 03:50	4.5	52%	61.0°
2043-06-30 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:45	4.51	41%	64.4°
2043-07-01 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:40	4.53	30%	69.5°
2043-07-02 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:40	4.56	20%	75.8°
2043-07-03 Fri	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:35	4.58	11%	82.9°
2043-07-04 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:30	4.61	5%	90.4°
2043-07-05 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:25	4.63	1%	97.9°
2043-07-06 Mon	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:20	4.66	0%	105.0°
2043-07-07 Tue	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:20	4.69	2%	111.1°
2043-07-08 Wed	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.3° 03:15	4.73	6%	116.0°
2043-07-09 Thu	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.3° 03:10	4.76	13%	119.3°
2043-07-10 Fri	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.3° 03:05	4.8	21%	120.8°
2043-07-11 Sat	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:00	4.83	30%	120.6°
2043-07-12 Sun	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:00	4.87	39%	118.8°
2043-07-13 Mon	100	—	unknown	23:00–03:55 (good, 4.92 h)	87.3° 02:55	4.91	49%	115.6°
2043-07-14 Tue	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.3° 02:50	4.95	58%	111.4°
2043-07-15 Wed	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:45	4.99	67%	106.4°
2043-07-16 Thu	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:45	5.04	76%	100.9°
2043-07-17 Fri	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.3° 02:40	5.08	84%	94.9°
2043-07-18 Sat	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.3° 02:35	5.13	90%	88.8°
2043-07-19 Sun	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.3° 02:30	5.17	95%	82.6°
2043-07-20 Mon	75	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:25	5.22	98%	76.6°
2043-07-21 Tue	69	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:25	5.27	100%	70.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-06-22&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.