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: 10-05 (100), 10-06 (100), 10-07 (100), 10-08 (100), 10-09 (100) — by astronomy; check the weather when the night is within four days.

2039-10-01astronomy score per night — click a bar for that night2039-10-30

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-10-01 Sat	65	—	unknown	20:40–21:55 (good, 1.25 h)	87.3° 21:40	9.17	100%	65.3°
2039-10-02 Sun	69	—	unknown	20:35–22:40 (good, 2.08 h)	87.3° 21:35	9.22	100%	68.7°
2039-10-03 Mon	73	—	unknown	20:35–23:55 (good, 3.33 h)	87.3° 21:30	9.27	97%	73.1°
2039-10-04 Tue	78	—	unknown	20:35–00:55 (good, 4.33 h)	87.3° 21:30	9.32	93%	78.0°
2039-10-05 Wed	100	—	unknown	20:30–01:45 (good, 5.25 h)	87.3° 21:25	9.36	87%	83.4°
2039-10-06 Thu	100	—	unknown	20:30–02:35 (good, 6.08 h)	87.3° 21:20	9.41	80%	88.9°
2039-10-07 Fri	100	—	unknown	20:30–03:05 (good, 6.58 h)	87.3° 21:15	9.46	72%	94.3°
2039-10-08 Sat	100	—	unknown	20:25–03:10 (good, 6.75 h)	87.2° 21:10	9.5	64%	99.6°
2039-10-09 Sun	100	—	unknown	20:25–03:15 (good, 6.83 h)	87.3° 21:10	9.55	54%	104.6°
2039-10-10 Mon	100	—	unknown	20:25–03:15 (good, 6.83 h)	87.3° 21:05	9.59	45%	109.1°
2039-10-11 Tue	100	—	unknown	20:20–03:15 (good, 6.92 h)	87.3° 21:00	9.64	35%	112.8°
2039-10-12 Wed	100	—	unknown	20:20–03:15 (good, 6.92 h)	87.3° 20:55	9.68	26%	115.6°
2039-10-13 Thu	100	—	unknown	20:20–03:15 (good, 6.92 h)	87.2° 20:55	9.73	18%	117.2°
2039-10-14 Fri	100	—	unknown	20:15–03:10 (good, 6.92 h)	87.3° 20:50	9.77	10%	117.3°
2039-10-15 Sat	100	—	unknown	20:15–03:05 (good, 6.83 h)	87.3° 20:45	9.81	5%	115.8°
2039-10-16 Sun	100	—	unknown	20:15–03:00 (good, 6.75 h)	87.3° 20:40	9.86	1%	112.7°
2039-10-17 Mon	100	—	unknown	20:10–02:55 (good, 6.75 h)	87.3° 20:35	9.9	0%	108.2°
2039-10-18 Tue	100	—	unknown	20:10–02:55 (good, 6.75 h)	87.3° 20:35	9.94	2%	102.6°
2039-10-19 Wed	100	—	unknown	20:10–02:50 (good, 6.67 h)	87.3° 20:30	9.99	6%	96.2°
2039-10-20 Thu	100	—	unknown	20:10–02:45 (good, 6.58 h)	87.3° 20:25	10.03	13%	89.4°
2039-10-21 Fri	100	—	unknown	20:05–02:40 (good, 6.58 h)	87.3° 20:20	10.07	22%	82.8°
2039-10-22 Sat	100	—	unknown	20:05–02:35 (good, 6.5 h)	87.2° 20:15	10.11	32%	76.6°
2039-10-23 Sun	99	—	unknown	20:05–02:35 (good, 6.5 h)	87.3° 20:15	10.15	44%	71.2°
2039-10-24 Mon	91	—	unknown	20:00–02:30 (good, 6.5 h)	87.3° 20:10	10.19	55%	66.9°
2039-10-25 Tue	82	—	unknown	20:00–02:25 (good, 6.42 h)	87.3° 20:05	10.23	66%	64.0°
2039-10-26 Wed	68	—	unknown	20:00–01:50 (good, 5.83 h)	87.3° 20:00	10.27	75%	62.7°
2039-10-27 Thu	65	—	unknown	20:00–23:20 (good, 3.33 h)	87.2° 20:00	10.31	84%	62.9°
2039-10-28 Fri	62	—	unknown	19:55–21:10 (good, 1.25 h)	87.3° 19:55	10.35	91%	64.6°
2039-10-29 Sat	60	—	unknown	19:55–21:00 (good, 1.08 h)	87.3° 19:50	10.38	96%	67.6°
2039-10-30 Sun	62	—	unknown	18:55–20:35 (good, 1.67 h)	87.3° 18:45	10.42	99%	71.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-10-01&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.