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: 09-20 (100), 09-21 (100), 09-22 (100), 09-23 (100), 09-24 (100) — by astronomy; check the weather when the night is within four days.

2035-09-08astronomy score per night — click a bar for that night2035-10-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-09-08 Sat	99	—	unknown	21:20–02:50 (good, 5.5 h)	87.1° 20:50	7.99	43%	62.7°
2035-09-09 Sun	94	—	unknown	21:20–02:45 (good, 5.42 h)	87.1° 20:45	8.04	53%	59.6°
2035-09-10 Mon	88	—	unknown	21:20–02:40 (good, 5.33 h)	87.1° 20:40	8.1	62%	57.8°
2035-09-11 Tue	82	—	unknown	21:15–02:35 (good, 5.33 h)	87.1° 20:35	8.15	71%	57.6°
2035-09-12 Wed	63	—	unknown	21:15–01:35 (good, 4.33 h)	87.1° 20:35	8.2	80%	59.0°
2035-09-13 Thu	56	—	unknown	21:10–23:50 (good, 2.67 h)	87.1° 20:30	8.26	87%	61.8°
2035-09-14 Fri	53	—	unknown	21:10–23:15 (good, 2.08 h)	87.1° 20:25	8.31	93%	65.9°
2035-09-15 Sat	54	—	unknown	21:10–23:15 (good, 2.08 h)	87.1° 20:20	8.36	97%	71.2°
2035-09-16 Sun	60	—	unknown	21:05–23:35 (good, 2.5 h)	87.1° 20:15	8.42	100%	77.3°
2035-09-17 Mon	67	—	unknown	21:05–00:05 (good, 3.0 h)	87.1° 20:15	8.47	100%	84.1°
2035-09-18 Tue	77	—	unknown	21:00–00:45 (good, 3.75 h)	87.1° 20:10	8.52	98%	91.3°
2035-09-19 Wed	85	—	unknown	21:00–01:30 (good, 4.5 h)	87.1° 20:05	8.57	94%	98.5°
2035-09-20 Thu	100	—	unknown	21:00–01:40 (good, 4.67 h)	87.1° 20:00	8.62	87%	105.4°
2035-09-21 Fri	100	—	unknown	20:55–01:40 (good, 4.75 h)	87.1° 20:00	8.67	79%	111.7°
2035-09-22 Sat	100	—	unknown	20:55–01:45 (good, 4.83 h)	87.1° 19:55	8.73	69%	116.9°
2035-09-23 Sun	100	—	unknown	20:55–01:45 (good, 4.83 h)	87.1° 19:50	8.78	58%	120.6°
2035-09-24 Mon	100	—	unknown	20:50–01:40 (good, 4.83 h)	87.1° 19:45	8.83	46%	122.3°
2035-09-25 Tue	100	—	unknown	20:50–01:40 (good, 4.83 h)	87.1° 19:40	8.88	35%	121.9°
2035-09-26 Wed	100	—	unknown	20:45–01:35 (good, 4.83 h)	87.1° 19:40	8.93	25%	119.3°
2035-09-27 Thu	100	—	unknown	20:45–01:35 (good, 4.83 h)	87.1° 19:35	8.98	16%	114.9°
2035-09-28 Fri	100	—	unknown	20:45–01:30 (good, 4.75 h)	87.1° 19:30	9.02	8%	109.1°
2035-09-29 Sat	100	—	unknown	20:40–01:25 (good, 4.75 h)	87.1° 19:25	9.07	3%	102.5°
2035-09-30 Sun	100	—	unknown	20:40–01:20 (good, 4.67 h)	87.1° 19:20	9.12	0%	95.4°
2035-10-01 Mon	100	—	unknown	20:40–01:20 (good, 4.67 h)	87.1° 19:20	9.17	0%	88.2°
2035-10-02 Tue	100	—	unknown	20:35–01:15 (good, 4.67 h)	87.1° 19:15	9.22	2%	81.2°
2035-10-03 Wed	100	—	unknown	20:35–01:10 (good, 4.58 h)	87.1° 19:10	9.27	6%	74.7°
2035-10-04 Thu	100	—	unknown	20:35–01:05 (good, 4.5 h)	87.1° 19:05	9.31	12%	69.0°
2035-10-05 Fri	100	—	unknown	20:30–01:00 (good, 4.5 h)	87.1° 19:05	9.36	19%	64.2°
2035-10-06 Sat	96	—	unknown	20:30–01:00 (good, 4.5 h)	87.1° 19:00	9.41	27%	60.6°
2035-10-07 Sun	91	—	unknown	20:30–00:55 (good, 4.42 h)	87.1° 18:55	9.45	36%	58.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-09-08&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.