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 Vega: 09-23 (100), 10-05 (100), 10-06 (100), 10-07 (100), 10-08 (100) — by astronomy; check the weather when the night is within four days.

2039-09-23astronomy score per night — click a bar for that night2039-10-22

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-09-23 Fri	100	—	unknown	20:55–01:50 (good, 4.92 h)	87.1° 19:50	8.78	36%	66.0°
2039-09-24 Sat	94	—	unknown	20:50–01:45 (good, 4.92 h)	87.1° 19:45	8.83	47%	64.2°
2039-09-25 Sun	87	—	unknown	20:50–01:40 (good, 4.83 h)	87.1° 19:40	8.88	58%	64.0°
2039-09-26 Mon	74	—	unknown	20:45–01:35 (good, 4.83 h)	87.1° 19:40	8.93	69%	65.5°
2039-09-27 Tue	63	—	unknown	20:45–01:05 (good, 4.33 h)	87.1° 19:35	8.98	79%	68.5°
2039-09-28 Wed	59	—	unknown	20:45–23:55 (good, 3.17 h)	87.1° 19:30	9.03	87%	72.7°
2039-09-29 Thu	59	—	unknown	20:40–23:25 (good, 2.75 h)	87.1° 19:25	9.08	94%	77.7°
2039-09-30 Fri	61	—	unknown	20:40–23:25 (good, 2.75 h)	87.1° 19:20	9.12	98%	83.2°
2039-10-01 Sat	65	—	unknown	20:40–23:40 (good, 3.0 h)	87.1° 19:20	9.17	100%	88.9°
2039-10-02 Sun	71	—	unknown	20:35–00:05 (good, 3.5 h)	87.1° 19:15	9.22	100%	94.5°
2039-10-03 Mon	78	—	unknown	20:35–00:35 (good, 4.0 h)	87.1° 19:10	9.27	97%	99.9°
2039-10-04 Tue	85	—	unknown	20:35–00:40 (good, 4.08 h)	87.1° 19:05	9.32	93%	104.8°
2039-10-05 Wed	100	—	unknown	20:30–00:40 (good, 4.17 h)	87.1° 19:05	9.36	87%	108.9°
2039-10-06 Thu	100	—	unknown	20:30–00:45 (good, 4.25 h)	87.1° 19:00	9.41	80%	112.2°
2039-10-07 Fri	100	—	unknown	20:30–00:45 (good, 4.25 h)	87.1° 18:55	9.46	72%	114.6°
2039-10-08 Sat	100	—	unknown	20:25–00:40 (good, 4.25 h)	87.1° 18:50	9.5	64%	115.8°
2039-10-09 Sun	100	—	unknown	20:25–00:40 (good, 4.25 h)	87.1° 18:45	9.55	54%	115.9°
2039-10-10 Mon	100	—	unknown	20:25–00:40 (good, 4.25 h)	87.1° 18:45	9.59	45%	114.8°
2039-10-11 Tue	100	—	unknown	20:20–00:40 (good, 4.33 h)	87.1° 18:40	9.64	35%	112.5°
2039-10-12 Wed	100	—	unknown	20:20–00:35 (good, 4.25 h)	87.1° 18:35	9.68	26%	109.1°
2039-10-13 Thu	100	—	unknown	20:20–00:30 (good, 4.17 h)	87.1° 18:30	9.73	18%	104.7°
2039-10-14 Fri	100	—	unknown	20:15–00:25 (good, 4.17 h)	87.1° 18:25	9.77	10%	99.5°
2039-10-15 Sat	100	—	unknown	20:15–00:25 (good, 4.17 h)	87.1° 18:25	9.81	5%	93.8°
2039-10-16 Sun	100	—	unknown	20:15–00:20 (good, 4.08 h)	87.1° 18:20	9.86	1%	87.7°
2039-10-17 Mon	100	—	unknown	20:10–00:15 (good, 4.08 h)	87.1° 18:15	9.9	0%	81.6°
2039-10-18 Tue	100	—	unknown	20:10–00:10 (good, 4.0 h)	87.1° 18:10	9.94	2%	75.8°
2039-10-19 Wed	100	—	unknown	20:10–00:05 (good, 3.92 h)	87.1° 18:05	9.99	6%	70.8°
2039-10-20 Thu	100	—	unknown	20:10–00:05 (good, 3.92 h)	87.1° 18:05	10.03	13%	66.9°
2039-10-21 Fri	95	—	unknown	20:05–00:00 (good, 3.92 h)	87.1° 18:00	10.07	22%	64.7°
2039-10-22 Sat	83	—	unknown	20:05–23:55 (good, 3.83 h)	87.1° 17:55	10.11	32%	64.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-09-23&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.