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: 08-25 (100), 08-26 (100), 08-27 (100), 08-28 (100), 08-29 (100) — by astronomy; check the weather when the night is within four days.

2041-08-25astronomy score per night — click a bar for that night2041-09-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-08-25 Sun	100	—	unknown	21:50–03:40 (good, 5.83 h)	87.1° 21:40	7.24	1%	106.8°
2041-08-26 Mon	100	—	unknown	21:45–03:35 (good, 5.83 h)	87.1° 21:40	7.29	0%	103.0°
2041-08-27 Tue	100	—	unknown	21:45–03:35 (good, 5.83 h)	87.1° 21:35	7.35	2%	98.8°
2041-08-28 Wed	100	—	unknown	21:45–03:30 (good, 5.75 h)	87.1° 21:30	7.41	5%	94.2°
2041-08-29 Thu	100	—	unknown	21:40–03:25 (good, 5.75 h)	87.1° 21:25	7.46	9%	89.5°
2041-08-30 Fri	100	—	unknown	21:40–03:20 (good, 5.67 h)	87.1° 21:20	7.52	16%	84.7°
2041-08-31 Sat	100	—	unknown	21:35–03:15 (good, 5.67 h)	87.1° 21:20	7.58	23%	80.1°
2041-09-01 Sun	100	—	unknown	21:35–03:15 (good, 5.67 h)	87.1° 21:15	7.63	32%	75.8°
2041-09-02 Mon	100	—	unknown	21:35–03:10 (good, 5.58 h)	87.1° 21:10	7.69	42%	72.0°
2041-09-03 Tue	100	—	unknown	21:30–03:05 (good, 5.58 h)	87.1° 21:05	7.74	52%	69.0°
2041-09-04 Wed	96	—	unknown	21:30–03:00 (good, 5.5 h)	87.1° 21:00	7.8	63%	67.0°
2041-09-05 Thu	88	—	unknown	21:25–03:00 (good, 5.58 h)	87.1° 21:00	7.85	73%	66.4°
2041-09-06 Fri	74	—	unknown	21:25–02:55 (good, 5.5 h)	87.1° 20:55	7.91	83%	67.2°
2041-09-07 Sat	65	—	unknown	21:25–01:20 (good, 3.92 h)	87.1° 20:50	7.96	91%	69.6°
2041-09-08 Sun	64	—	unknown	21:20–00:25 (good, 3.08 h)	87.1° 20:45	8.02	96%	73.4°
2041-09-09 Mon	66	—	unknown	21:20–00:20 (good, 3.0 h)	87.1° 20:45	8.07	100%	78.4°
2041-09-10 Tue	72	—	unknown	21:15–00:35 (good, 3.33 h)	87.1° 20:40	8.13	100%	84.1°
2041-09-11 Wed	80	—	unknown	21:15–01:10 (good, 3.92 h)	87.1° 20:35	8.18	96%	90.1°
2041-09-12 Thu	84	—	unknown	21:15–01:45 (good, 4.5 h)	87.1° 20:30	8.23	91%	96.0°
2041-09-13 Fri	100	—	unknown	21:10–02:00 (good, 4.83 h)	87.1° 20:25	8.29	83%	101.4°
2041-09-14 Sat	100	—	unknown	21:10–02:05 (good, 4.92 h)	87.1° 20:25	8.34	74%	105.9°
2041-09-15 Sun	100	—	unknown	21:05–02:05 (good, 5.0 h)	87.1° 20:20	8.39	63%	109.5°
2041-09-16 Mon	100	—	unknown	21:05–02:05 (good, 5.0 h)	87.1° 20:15	8.44	53%	112.0°
2041-09-17 Tue	100	—	unknown	21:05–02:05 (good, 5.0 h)	87.1° 20:10	8.5	43%	113.3°
2041-09-18 Wed	100	—	unknown	21:00–02:05 (good, 5.08 h)	87.1° 20:05	8.55	33%	113.4°
2041-09-19 Thu	100	—	unknown	21:00–02:00 (good, 5.0 h)	87.1° 20:05	8.6	25%	112.4°
2041-09-20 Fri	100	—	unknown	20:55–02:00 (good, 5.08 h)	87.1° 20:00	8.65	17%	110.4°
2041-09-21 Sat	100	—	unknown	20:55–01:55 (good, 5.0 h)	87.1° 19:55	8.7	10%	107.6°
2041-09-22 Sun	100	—	unknown	20:55–01:50 (good, 4.92 h)	87.1° 19:50	8.75	5%	104.0°
2041-09-23 Mon	100	—	unknown	20:50–01:45 (good, 4.92 h)	87.1° 19:50	8.8	2%	99.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-08-25&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.