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 3C 273: 01-02 (93), 01-03 (93), 01-04 (93), 01-05 (93), 01-06 (93) — by astronomy; check the weather when the night is within four days.

2029-12-18astronomy score per night — click a bar for that night2030-01-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-12-18 Tue	58	—	unknown	03:25–06:05 (good, 2.67 h)	50.2° 07:00	11.5	96%	120.7°
2029-12-19 Wed	51	—	unknown	03:30–06:05 (good, 2.58 h)	50.2° 06:55	11.51	99%	108.8°
2029-12-20 Thu	42	—	unknown	03:55–06:05 (good, 2.17 h)	50.2° 06:50	11.51	100%	96.8°
2029-12-21 Fri	34	—	unknown	05:10–06:05 (good, 0.92 h)	50.2° 06:50	11.51	99%	84.5°
2029-12-22 Sat	28	—	unknown	02:50–06:10 (marginal, 3.33 h)	50.2° 06:45	11.51	96%	72.1°
2029-12-23 Sun	23	—	unknown	02:55–06:10 (marginal, 3.25 h)	50.2° 06:40	11.51	91%	59.5°
2029-12-24 Mon	20	—	unknown	02:55–06:10 (marginal, 3.25 h)	50.2° 06:35	11.5	84%	46.9°
2029-12-25 Tue	20	—	unknown	02:45–06:10 (marginal, 3.42 h)	50.2° 06:30	11.5	76%	34.1°
2029-12-26 Wed	25	—	unknown	02:30–06:10 (marginal, 3.67 h)	50.2° 06:30	11.49	66%	21.7°
2029-12-27 Thu	35	—	unknown	02:15–06:10 (marginal, 3.92 h)	50.2° 06:25	11.49	55%	11.5°
2029-12-28 Fri	46	—	unknown	03:00–06:10 (good, 3.17 h)	50.2° 06:20	11.48	44%	12.9°
2029-12-29 Sat	60	—	unknown	02:45–06:10 (good, 3.42 h)	50.2° 06:15	11.48	33%	24.4°
2029-12-30 Sun	76	—	unknown	02:25–06:10 (good, 3.75 h)	50.2° 06:10	11.47	23%	37.9°
2029-12-31 Mon	87	—	unknown	02:20–06:10 (good, 3.83 h)	50.2° 06:10	11.46	14%	52.0°
2030-01-01 Tue	92	—	unknown	02:15–06:10 (good, 3.92 h)	50.2° 06:05	11.45	6%	66.4°
2030-01-02 Wed	93	—	unknown	02:15–06:10 (good, 3.92 h)	50.2° 06:00	11.44	2%	80.8°
2030-01-03 Thu	93	—	unknown	02:10–06:10 (good, 4.0 h)	50.2° 05:55	11.43	0%	95.1°
2030-01-04 Fri	93	—	unknown	02:05–06:10 (good, 4.08 h)	50.2° 05:55	11.42	1%	109.2°
2030-01-05 Sat	93	—	unknown	02:00–06:10 (good, 4.17 h)	50.2° 05:50	11.4	4%	122.9°
2030-01-06 Sun	93	—	unknown	02:00–06:10 (good, 4.17 h)	50.2° 05:45	11.39	10%	136.1°
2030-01-07 Mon	93	—	unknown	01:55–06:10 (good, 4.25 h)	50.2° 05:40	11.37	17%	148.7°
2030-01-08 Tue	93	—	unknown	01:50–06:10 (good, 4.33 h)	50.2° 05:35	11.36	25%	160.3°
2030-01-09 Wed	93	—	unknown	01:45–06:10 (good, 4.42 h)	50.2° 05:35	11.34	34%	169.1°
2030-01-10 Thu	93	—	unknown	01:40–06:10 (good, 4.5 h)	50.2° 05:30	11.32	44%	167.6°
2030-01-11 Fri	93	—	unknown	01:40–06:10 (good, 4.5 h)	50.2° 05:25	11.3	53%	158.3°
2030-01-12 Sat	93	—	unknown	01:40–06:10 (good, 4.5 h)	50.2° 05:20	11.29	63%	147.3°
2030-01-13 Sun	93	—	unknown	01:35–06:10 (good, 4.58 h)	50.2° 05:15	11.27	71%	136.0°
2030-01-14 Mon	93	—	unknown	01:35–06:10 (good, 4.58 h)	50.2° 05:15	11.25	80%	124.4°
2030-01-15 Tue	93	—	unknown	01:35–06:10 (good, 4.58 h)	50.2° 05:10	11.22	87%	112.6°
2030-01-16 Wed	93	—	unknown	01:45–06:10 (good, 4.42 h)	50.2° 05:05	11.2	93%	100.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-12-18&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.