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: 09-01 (100), 09-02 (100), 09-03 (100), 09-04 (100), 09-05 (100) — by astronomy; check the weather when the night is within four days.

2034-08-26astronomy score per night — click a bar for that night2034-09-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-08-26 Sat	56	—	unknown	21:45–04:10 (marginal, 6.42 h)	87.1° 21:40	7.28	91%	58.4°
2034-08-27 Sun	53	—	unknown	21:10–04:00 (marginal, 6.83 h)	87.1° 21:35	7.33	96%	61.7°
2034-08-28 Mon	56	—	unknown	21:45–22:35 (good, 0.83 h)	87.1° 21:30	7.39	99%	66.6°
2034-08-29 Tue	62	—	unknown	21:40–00:10 (good, 2.5 h)	87.1° 21:25	7.45	100%	72.7°
2034-08-30 Wed	72	—	unknown	21:40–00:55 (good, 3.25 h)	87.1° 21:25	7.5	98%	79.9°
2034-08-31 Thu	80	—	unknown	21:35–01:45 (good, 4.17 h)	87.1° 21:20	7.56	94%	87.5°
2034-09-01 Fri	100	—	unknown	21:35–02:40 (good, 5.08 h)	87.1° 21:15	7.61	87%	95.4°
2034-09-02 Sat	100	—	unknown	21:35–02:50 (good, 5.25 h)	87.1° 21:10	7.67	78%	103.0°
2034-09-03 Sun	100	—	unknown	21:30–02:55 (good, 5.42 h)	87.1° 21:05	7.73	68%	110.0°
2034-09-04 Mon	100	—	unknown	21:30–02:55 (good, 5.42 h)	87.1° 21:05	7.78	56%	115.9°
2034-09-05 Tue	100	—	unknown	21:25–02:55 (good, 5.5 h)	87.1° 21:00	7.84	45%	120.3°
2034-09-06 Wed	100	—	unknown	21:25–02:50 (good, 5.42 h)	87.1° 20:55	7.89	34%	122.8°
2034-09-07 Thu	100	—	unknown	21:25–02:50 (good, 5.42 h)	87.1° 20:50	7.95	24%	123.1°
2034-09-08 Fri	100	—	unknown	21:20–02:45 (good, 5.42 h)	87.1° 20:50	8.0	15%	121.4°
2034-09-09 Sat	100	—	unknown	21:20–02:45 (good, 5.42 h)	87.1° 20:45	8.05	8%	117.8°
2034-09-10 Sun	100	—	unknown	21:15–02:40 (good, 5.42 h)	87.1° 20:40	8.11	3%	112.8°
2034-09-11 Mon	100	—	unknown	21:15–02:35 (good, 5.33 h)	87.1° 20:35	8.16	1%	106.9°
2034-09-12 Tue	100	—	unknown	21:15–02:30 (good, 5.25 h)	87.1° 20:30	8.22	0%	100.4°
2034-09-13 Wed	100	—	unknown	21:10–02:25 (good, 5.25 h)	87.1° 20:30	8.27	2%	93.6°
2034-09-14 Thu	100	—	unknown	21:10–02:25 (good, 5.25 h)	87.1° 20:25	8.32	5%	86.8°
2034-09-15 Fri	100	—	unknown	21:10–02:20 (good, 5.17 h)	87.1° 20:20	8.38	10%	80.3°
2034-09-16 Sat	100	—	unknown	21:05–02:15 (good, 5.17 h)	87.1° 20:15	8.43	17%	74.2°
2034-09-17 Sun	100	—	unknown	21:05–02:10 (good, 5.08 h)	87.1° 20:10	8.48	24%	68.6°
2034-09-18 Mon	100	—	unknown	21:00–02:10 (good, 5.17 h)	87.1° 20:10	8.53	33%	63.8°
2034-09-19 Tue	95	—	unknown	21:00–02:05 (good, 5.08 h)	87.1° 20:05	8.58	42%	60.1°
2034-09-20 Wed	89	—	unknown	21:00–02:00 (good, 5.0 h)	87.1° 20:00	8.64	51%	57.7°
2034-09-21 Thu	83	—	unknown	20:55–01:55 (good, 5.0 h)	87.1° 19:55	8.69	61%	56.8°
2034-09-22 Fri	65	—	unknown	20:55–01:25 (good, 4.5 h)	87.1° 19:55	8.74	71%	57.6°
2034-09-23 Sat	55	—	unknown	20:50–23:55 (good, 3.08 h)	87.1° 19:50	8.79	79%	60.1°
2034-09-24 Sun	51	—	unknown	20:50–22:50 (good, 2.0 h)	87.1° 19:45	8.84	87%	64.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-08-26&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.