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: 09-30 (100), 10-01 (100), 10-02 (100), 10-03 (100), 10-04 (100) — by astronomy; check the weather when the night is within four days.

2043-09-30astronomy score per night — click a bar for that night2043-10-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-09-30 Wed	100	—	unknown	20:40–04:05 (good, 7.42 h)	87.3° 21:45	9.13	5%	120.9°
2043-10-01 Thu	100	—	unknown	20:40–04:00 (good, 7.33 h)	87.3° 21:40	9.17	2%	120.8°
2043-10-02 Fri	100	—	unknown	20:35–03:55 (good, 7.33 h)	87.3° 21:35	9.22	0%	119.1°
2043-10-03 Sat	100	—	unknown	20:35–03:50 (good, 7.25 h)	87.2° 21:30	9.27	1%	116.0°
2043-10-04 Sun	100	—	unknown	20:35–03:50 (good, 7.25 h)	87.2° 21:30	9.32	3%	111.7°
2043-10-05 Mon	100	—	unknown	20:30–03:45 (good, 7.25 h)	87.3° 21:25	9.36	7%	106.6°
2043-10-06 Tue	100	—	unknown	20:30–03:40 (good, 7.17 h)	87.3° 21:20	9.41	13%	101.0°
2043-10-07 Wed	100	—	unknown	20:30–03:35 (good, 7.08 h)	87.3° 21:15	9.46	20%	95.1°
2043-10-08 Thu	100	—	unknown	20:25–03:30 (good, 7.08 h)	87.2° 21:10	9.5	28%	89.0°
2043-10-09 Fri	100	—	unknown	20:25–03:30 (good, 7.08 h)	87.2° 21:10	9.55	37%	82.9°
2043-10-10 Sat	100	—	unknown	20:25–03:25 (good, 7.0 h)	87.3° 21:05	9.59	46%	77.0°
2043-10-11 Sun	98	—	unknown	20:20–03:20 (good, 7.0 h)	87.3° 21:00	9.64	56%	71.5°
2043-10-12 Mon	89	—	unknown	20:20–03:15 (good, 6.92 h)	87.2° 20:55	9.68	66%	66.5°
2043-10-13 Tue	81	—	unknown	20:20–03:15 (good, 6.92 h)	87.2° 20:55	9.73	75%	62.5°
2043-10-14 Wed	64	—	unknown	20:15–00:35 (good, 4.33 h)	87.3° 20:50	9.77	84%	59.8°
2043-10-15 Thu	60	—	unknown	19:45–03:30 (marginal, 7.75 h)	87.3° 20:45	9.82	91%	58.9°
2043-10-16 Fri	55	—	unknown	20:15–03:15 (marginal, 7.0 h)	87.3° 20:40	9.86	96%	60.0°
2043-10-17 Sat	55	—	unknown	20:10–20:25 (good, 0.25 h)	87.2° 20:35	9.9	100%	63.1°
2043-10-18 Sun	62	—	unknown	20:10–21:25 (good, 1.25 h)	87.2° 20:35	9.94	100%	68.1°
2043-10-19 Mon	72	—	unknown	20:10–23:15 (good, 3.08 h)	87.3° 20:30	9.99	97%	74.5°
2043-10-20 Tue	78	—	unknown	20:10–00:20 (good, 4.17 h)	87.3° 20:25	10.03	91%	81.7°
2043-10-21 Wed	100	—	unknown	20:05–01:35 (good, 5.5 h)	87.3° 20:20	10.07	84%	89.3°
2043-10-22 Thu	100	—	unknown	20:05–02:10 (good, 6.08 h)	87.2° 20:15	10.11	74%	96.8°
2043-10-23 Fri	100	—	unknown	20:05–02:15 (good, 6.17 h)	87.2° 20:15	10.15	63%	103.8°
2043-10-24 Sat	100	—	unknown	20:00–02:20 (good, 6.33 h)	87.3° 20:10	10.19	52%	110.0°
2043-10-25 Sun	100	—	unknown	19:00–01:20 (good, 6.33 h)	87.3° 19:05	10.23	41%	115.1°
2043-10-26 Mon	100	—	unknown	19:00–01:20 (good, 6.33 h)	87.2° 19:00	10.27	31%	118.7°
2043-10-27 Tue	100	—	unknown	19:00–01:20 (good, 6.33 h)	87.2° 19:00	10.31	22%	120.7°
2043-10-28 Wed	100	—	unknown	18:55–01:15 (good, 6.33 h)	87.3° 18:55	10.35	14%	121.1°
2043-10-29 Thu	100	—	unknown	18:55–01:10 (good, 6.25 h)	87.3° 18:50	10.39	8%	119.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-09-30&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.