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: 10-13 (100), 10-14 (100), 10-15 (100), 10-16 (100), 10-17 (100) — by astronomy; check the weather when the night is within four days.

2039-10-13astronomy score per night — click a bar for that night2039-11-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2039-10-23 Sun	74	—	unknown	20:05–23:50 (good, 3.75 h)	87.1° 17:50	10.15	44%	65.3°
2039-10-24 Mon	64	—	unknown	20:00–23:30 (good, 3.5 h)	87.1° 17:50	10.19	55%	67.9°
2039-10-25 Tue	57	—	unknown	20:00–23:20 (good, 3.33 h)	87.1° 17:45	10.23	66%	71.8°
2039-10-26 Wed	52	—	unknown	20:00–22:55 (good, 2.92 h)	87.1° 17:40	10.27	75%	76.5°
2039-10-27 Thu	49	—	unknown	20:00–22:25 (good, 2.42 h)	87.1° 17:35	10.31	84%	81.8°
2039-10-28 Fri	50	—	unknown	19:55–22:15 (good, 2.33 h)	87.1° 17:30	10.35	91%	87.3°
2039-10-29 Sat	52	—	unknown	19:55–22:20 (good, 2.42 h)	87.1° 17:30	10.38	96%	92.9°
2039-10-30 Sun	55	—	unknown	18:55–21:35 (good, 2.67 h)	87.1° 16:25	10.42	99%	98.3°
2039-10-31 Mon	58	—	unknown	18:55–21:50 (good, 2.92 h)	87.1° 16:20	10.46	100%	103.3°
2039-11-01 Tue	63	—	unknown	18:50–21:50 (good, 3.0 h)	87.1° 16:15	10.5	99%	107.6°
2039-11-02 Wed	67	—	unknown	18:50–21:50 (good, 3.0 h)	87.1° 16:10	10.53	96%	111.2°
2039-11-03 Thu	77	—	unknown	18:50–21:50 (good, 3.0 h)	87.1° 16:10	10.57	92%	113.8°
2039-11-04 Fri	79	—	unknown	18:50–21:50 (good, 3.0 h)	87.1° 16:05	10.6	86%	115.4°
2039-11-05 Sat	79	—	unknown	18:50–21:50 (good, 3.0 h)	87.1° 16:00	10.64	79%	115.8°
2039-11-06 Sun	81	—	unknown	18:45–21:50 (good, 3.08 h)	87.1° 15:55	10.67	71%	115.1°
2039-11-07 Mon	80	—	unknown	18:45–21:50 (good, 3.08 h)	87.1° 15:55	10.71	62%	113.2°
2039-11-08 Tue	79	—	unknown	18:45–21:50 (good, 3.08 h)	87.1° 15:50	10.74	52%	110.2°
2039-11-09 Wed	77	—	unknown	18:45–21:45 (good, 3.0 h)	87.1° 15:45	10.77	42%	106.3°
2039-11-10 Thu	75	—	unknown	18:45–21:40 (good, 2.92 h)	87.1° 15:40	10.8	33%	101.5°
2039-11-11 Fri	74	—	unknown	18:45–21:35 (good, 2.83 h)	87.1° 15:35	10.83	23%	96.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-10-13&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.