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: 02-10 (54), 02-09 (53), 02-11 (53), 02-08 (52), 02-07 (51) — by astronomy; check the weather when the night is within four days.

2041-01-23astronomy score per night — click a bar for that night2041-02-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-01-23 Wed	21	—	unknown	05:15–06:05 (good, 0.83 h)	87.1° 10:45	11.02	65%	86.7°
2041-01-24 Thu	23	—	unknown	05:05–06:05 (good, 1.0 h)	87.1° 10:40	10.99	55%	81.7°
2041-01-25 Fri	25	—	unknown	04:55–06:05 (good, 1.17 h)	87.1° 10:35	10.96	45%	76.9°
2041-01-26 Sat	29	—	unknown	04:50–06:05 (good, 1.25 h)	87.1° 10:30	10.93	34%	72.6°
2041-01-27 Sun	33	—	unknown	04:40–06:05 (good, 1.42 h)	87.1° 10:25	10.9	24%	69.0°
2041-01-28 Mon	38	—	unknown	04:30–06:05 (good, 1.58 h)	87.1° 10:25	10.87	15%	66.6°
2041-01-29 Tue	40	—	unknown	04:25–06:00 (good, 1.58 h)	87.1° 10:20	10.84	8%	65.7°
2041-01-30 Wed	42	—	unknown	04:20–06:00 (good, 1.67 h)	87.1° 10:15	10.81	3%	66.4°
2041-01-31 Thu	43	—	unknown	04:15–06:00 (good, 1.75 h)	87.1° 10:10	10.78	0%	68.9°
2041-02-01 Fri	44	—	unknown	04:15–06:00 (good, 1.75 h)	87.1° 10:10	10.75	1%	72.9°
2041-02-02 Sat	45	—	unknown	04:10–06:00 (good, 1.83 h)	87.1° 10:05	10.71	5%	78.0°
2041-02-03 Sun	46	—	unknown	04:05–05:55 (good, 1.83 h)	87.1° 10:00	10.68	11%	83.7°
2041-02-04 Mon	47	—	unknown	04:00–05:55 (good, 1.92 h)	87.1° 09:55	10.64	19%	89.6°
2041-02-05 Tue	49	—	unknown	04:00–05:55 (good, 1.92 h)	87.1° 09:50	10.61	29%	95.4°
2041-02-06 Wed	50	—	unknown	03:55–05:55 (good, 2.0 h)	87.1° 09:50	10.57	39%	100.7°
2041-02-07 Thu	51	—	unknown	03:50–05:55 (good, 2.08 h)	87.1° 09:45	10.54	50%	105.3°
2041-02-08 Fri	52	—	unknown	03:45–05:50 (good, 2.08 h)	87.1° 09:40	10.5	60%	109.1°
2041-02-09 Sat	53	—	unknown	03:40–05:50 (good, 2.17 h)	87.1° 09:35	10.46	69%	111.9°
2041-02-10 Sun	54	—	unknown	03:45–05:50 (good, 2.08 h)	87.1° 09:30	10.43	78%	113.7°
2041-02-11 Mon	53	—	unknown	03:45–05:50 (good, 2.08 h)	87.1° 09:30	10.39	85%	114.3°
2041-02-12 Tue	47	—	unknown	03:45–05:50 (good, 2.08 h)	87.1° 09:25	10.35	91%	113.8°
2041-02-13 Wed	44	—	unknown	03:45–05:45 (good, 2.0 h)	87.1° 09:20	10.31	96%	112.2°
2041-02-14 Thu	43	—	unknown	03:45–05:45 (good, 2.0 h)	87.1° 09:15	10.27	99%	109.7°
2041-02-15 Fri	41	—	unknown	03:45–05:45 (good, 2.0 h)	87.1° 09:15	10.23	100%	106.4°
2041-02-16 Sat	38	—	unknown	03:45–05:45 (good, 2.0 h)	87.1° 09:10	10.19	99%	102.4°
2041-02-17 Sun	36	—	unknown	03:55–05:40 (good, 1.75 h)	87.1° 09:05	10.15	97%	97.9°
2041-02-18 Mon	35	—	unknown	04:05–05:40 (good, 1.58 h)	87.1° 09:00	10.11	93%	93.1°
2041-02-19 Tue	35	—	unknown	04:05–05:40 (good, 1.58 h)	87.1° 08:55	10.07	87%	88.1°
2041-02-20 Wed	37	—	unknown	03:50–05:40 (good, 1.83 h)	87.1° 08:55	10.03	80%	83.1°
2041-02-21 Thu	38	—	unknown	03:25–05:35 (good, 2.17 h)	87.1° 08:50	9.98	71%	78.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-01-23&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.