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: 09-26 (100), 09-27 (100), 09-28 (100), 09-29 (100), 09-30 (100) — by astronomy; check the weather when the night is within four days.

2029-09-23astronomy score per night — click a bar for that night2029-10-22

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-09-23 Sun	65	—	unknown	20:50–23:40 (good, 2.83 h)	87.1° 19:50	8.8	98%	85.5°
2029-09-24 Mon	74	—	unknown	20:50–00:20 (good, 3.5 h)	87.1° 19:45	8.85	95%	91.5°
2029-09-25 Tue	83	—	unknown	20:50–01:00 (good, 4.17 h)	87.1° 19:40	8.9	91%	97.3°
2029-09-26 Wed	100	—	unknown	20:45–01:10 (good, 4.42 h)	87.1° 19:35	8.95	84%	102.9°
2029-09-27 Thu	100	—	unknown	20:45–01:15 (good, 4.5 h)	87.1° 19:30	9.0	77%	108.1°
2029-09-28 Fri	100	—	unknown	20:45–01:15 (good, 4.5 h)	87.1° 19:30	9.05	69%	112.7°
2029-09-29 Sat	100	—	unknown	20:40–01:15 (good, 4.58 h)	87.1° 19:25	9.1	59%	116.3°
2029-09-30 Sun	100	—	unknown	20:40–01:15 (good, 4.58 h)	87.1° 19:20	9.14	50%	118.9°
2029-10-01 Mon	100	—	unknown	20:35–01:10 (good, 4.58 h)	87.1° 19:15	9.19	39%	120.0°
2029-10-02 Tue	100	—	unknown	20:35–01:10 (good, 4.58 h)	87.1° 19:10	9.24	29%	119.5°
2029-10-03 Wed	100	—	unknown	20:35–01:10 (good, 4.58 h)	87.1° 19:10	9.29	20%	117.2°
2029-10-04 Thu	100	—	unknown	20:30–01:05 (good, 4.58 h)	87.1° 19:05	9.34	12%	113.1°
2029-10-05 Fri	100	—	unknown	20:30–01:00 (good, 4.5 h)	87.1° 19:00	9.38	5%	107.6°
2029-10-06 Sat	100	—	unknown	20:30–00:55 (good, 4.42 h)	87.1° 18:55	9.43	1%	101.0°
2029-10-07 Sun	100	—	unknown	20:25–00:50 (good, 4.42 h)	87.1° 18:55	9.48	0%	93.6°
2029-10-08 Mon	100	—	unknown	20:25–00:50 (good, 4.42 h)	87.1° 18:50	9.52	2%	86.0°
2029-10-09 Tue	100	—	unknown	20:25–00:45 (good, 4.33 h)	87.1° 18:45	9.57	7%	78.6°
2029-10-10 Wed	100	—	unknown	20:20–00:40 (good, 4.33 h)	87.1° 18:40	9.61	14%	72.0°
2029-10-11 Thu	100	—	unknown	20:20–00:35 (good, 4.25 h)	87.1° 18:35	9.66	23%	66.5°
2029-10-12 Fri	92	—	unknown	20:20–00:30 (good, 4.17 h)	87.1° 18:35	9.7	33%	62.5°
2029-10-13 Sat	80	—	unknown	20:20–00:30 (good, 4.17 h)	87.1° 18:30	9.75	44%	60.3°
2029-10-14 Sun	66	—	unknown	20:15–00:05 (good, 3.83 h)	87.1° 18:25	9.79	55%	59.9°
2029-10-15 Mon	56	—	unknown	20:15–23:50 (good, 3.58 h)	87.1° 18:20	9.83	65%	61.2°
2029-10-16 Tue	48	—	unknown	20:15–22:30 (good, 2.25 h)	87.1° 18:15	9.88	74%	64.0°
2029-10-17 Wed	44	—	unknown	20:10–21:40 (good, 1.5 h)	87.1° 18:15	9.92	82%	68.0°
2029-10-18 Thu	42	—	unknown	20:10–21:25 (good, 1.25 h)	87.1° 18:10	9.96	89%	72.8°
2029-10-19 Fri	43	—	unknown	20:10–21:30 (good, 1.33 h)	87.1° 18:05	10.0	94%	78.2°
2029-10-20 Sat	47	—	unknown	20:05–21:45 (good, 1.67 h)	87.1° 18:00	10.05	98%	84.0°
2029-10-21 Sun	51	—	unknown	20:05–22:10 (good, 2.08 h)	87.1° 18:00	10.09	100%	89.9°
2029-10-22 Mon	57	—	unknown	20:05–22:45 (good, 2.67 h)	87.1° 17:55	10.13	100%	95.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-09-23&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.