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: 09-12 (100), 09-13 (100), 09-26 (100), 09-27 (100), 09-28 (100) — by astronomy; check the weather when the night is within four days.

2029-09-12astronomy score per night — click a bar for that night2029-10-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-09-12 Wed	100	—	unknown	21:15–02:30 (good, 5.25 h)	87.1° 20:30	8.23	27%	76.3°
2029-09-13 Thu	100	—	unknown	21:10–02:25 (good, 5.25 h)	87.1° 20:25	8.28	37%	70.2°
2029-09-14 Fri	98	—	unknown	21:10–02:20 (good, 5.17 h)	87.1° 20:25	8.33	48%	65.4°
2029-09-15 Sat	89	—	unknown	21:05–02:20 (good, 5.25 h)	87.1° 20:20	8.39	60%	62.0°
2029-09-16 Sun	81	—	unknown	21:05–02:15 (good, 5.17 h)	87.1° 20:15	8.44	70%	60.3°
2029-09-17 Mon	60	—	unknown	21:05–01:05 (good, 4.0 h)	87.1° 20:10	8.49	79%	60.3°
2029-09-18 Tue	53	—	unknown	21:00–23:10 (good, 2.17 h)	87.1° 20:05	8.54	86%	62.0°
2029-09-19 Wed	49	—	unknown	21:00–21:50 (good, 0.83 h)	87.1° 20:05	8.59	93%	65.1°
2029-09-20 Thu	48	—	unknown	21:00–21:55 (good, 0.92 h)	87.1° 20:00	8.65	97%	69.2°
2029-09-21 Fri	51	—	unknown	20:55–22:40 (good, 1.75 h)	87.1° 19:55	8.7	99%	74.2°
2029-09-22 Sat	57	—	unknown	20:55–23:05 (good, 2.17 h)	87.1° 19:50	8.75	100%	79.7°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-09-12&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.