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), 09-24 (100), 09-25 (100), 09-26 (100), 09-27 (100) — by astronomy; check the weather when the night is within four days.

2035-09-23astronomy score per night — click a bar for that night2035-10-22

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2035-10-08 Mon	85	—	unknown	20:25–00:50 (good, 4.42 h)	87.1° 18:50	9.5	45%	57.7°
2035-10-09 Tue	71	—	unknown	20:25–00:45 (good, 4.33 h)	87.1° 18:45	9.55	55%	58.4°
2035-10-10 Wed	60	—	unknown	20:25–00:15 (good, 3.83 h)	87.1° 18:45	9.59	64%	60.7°
2035-10-11 Thu	54	—	unknown	20:20–23:30 (good, 3.17 h)	87.1° 18:40	9.64	73%	64.4°
2035-10-12 Fri	50	—	unknown	20:20–22:35 (good, 2.25 h)	87.1° 18:35	9.68	81%	69.2°
2035-10-13 Sat	49	—	unknown	20:20–22:20 (good, 2.0 h)	87.1° 18:30	9.73	89%	75.0°
2035-10-14 Sun	52	—	unknown	20:15–22:25 (good, 2.17 h)	87.1° 18:25	9.77	94%	81.6°
2035-10-15 Mon	56	—	unknown	20:15–22:45 (good, 2.5 h)	87.1° 18:25	9.81	98%	88.6°
2035-10-16 Tue	62	—	unknown	20:15–23:15 (good, 3.0 h)	87.1° 18:20	9.86	100%	95.9°
2035-10-17 Wed	70	—	unknown	20:10–23:45 (good, 3.58 h)	87.1° 18:15	9.9	99%	103.1°
2035-10-18 Thu	78	—	unknown	20:10–23:50 (good, 3.67 h)	87.1° 18:10	9.94	96%	109.8°
2035-10-19 Fri	94	—	unknown	20:10–23:50 (good, 3.67 h)	87.1° 18:05	9.98	90%	115.5°
2035-10-20 Sat	97	—	unknown	20:10–23:55 (good, 3.75 h)	87.1° 18:05	10.03	82%	119.7°
2035-10-21 Sun	99	—	unknown	20:05–23:50 (good, 3.75 h)	87.1° 18:00	10.07	72%	122.0°
2035-10-22 Mon	99	—	unknown	20:05–23:50 (good, 3.75 h)	87.1° 17:55	10.11	61%	122.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-09-23&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.