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: 12-31 (87), 12-30 (76), 12-15 (64), 12-16 (64), 12-17 (63) — by astronomy; check the weather when the night is within four days.

2029-12-02astronomy score per night — click a bar for that night2029-12-31

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-12-02 Sun	38	—	unknown	04:15–05:55 (good, 1.67 h)	50.2° 08:00	11.35	11%	28.8°
2029-12-03 Mon	42	—	unknown	04:10–05:55 (good, 1.75 h)	50.2° 08:00	11.37	4%	43.1°
2029-12-04 Tue	44	—	unknown	04:05–05:55 (good, 1.83 h)	50.2° 07:55	11.38	1%	57.8°
2029-12-05 Wed	46	—	unknown	04:05–05:55 (good, 1.83 h)	50.2° 07:50	11.4	0%	72.5°
2029-12-06 Thu	47	—	unknown	04:00–05:55 (good, 1.92 h)	50.2° 07:45	11.41	2%	87.1°
2029-12-07 Fri	50	—	unknown	03:55–06:00 (good, 2.08 h)	50.2° 07:45	11.42	7%	101.4°
2029-12-08 Sat	51	—	unknown	03:50–06:00 (good, 2.17 h)	50.2° 07:40	11.44	14%	115.2°
2029-12-09 Sun	53	—	unknown	03:50–06:00 (good, 2.17 h)	50.2° 07:35	11.45	23%	128.4°
2029-12-10 Mon	55	—	unknown	03:45–06:00 (good, 2.25 h)	50.2° 07:30	11.46	32%	141.1°
2029-12-11 Tue	57	—	unknown	03:40–06:00 (good, 2.33 h)	50.2° 07:25	11.47	42%	153.1°
2029-12-12 Wed	58	—	unknown	03:35–06:00 (good, 2.42 h)	50.2° 07:25	11.47	52%	163.9°
2029-12-13 Thu	60	—	unknown	03:30–06:05 (good, 2.58 h)	50.2° 07:20	11.48	61%	170.0°
2029-12-14 Fri	62	—	unknown	03:30–06:05 (good, 2.58 h)	50.2° 07:15	11.49	70%	165.0°
2029-12-15 Sat	64	—	unknown	03:25–06:05 (good, 2.67 h)	50.2° 07:10	11.49	79%	154.9°
2029-12-16 Sun	64	—	unknown	03:30–06:05 (good, 2.58 h)	50.2° 07:05	11.5	86%	143.8°
2029-12-17 Mon	63	—	unknown	03:25–06:05 (good, 2.67 h)	50.2° 07:05	11.5	92%	132.4°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-12-02&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.