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: 12-30 (88), 12-29 (87), 12-28 (86), 12-27 (84), 12-26 (82) — by astronomy; check the weather when the night is within four days.

2046-12-01astronomy score per night — click a bar for that night2046-12-30

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-12-01 Sat	38	—	unknown	04:20–05:55 (good, 1.58 h)	50.1° 08:10	11.33	19%	115.1°
2046-12-02 Sun	40	—	unknown	04:15–05:55 (good, 1.67 h)	50.1° 08:05	11.35	27%	127.7°
2046-12-03 Mon	42	—	unknown	04:15–05:55 (good, 1.67 h)	50.1° 08:00	11.37	36%	139.8°
2046-12-04 Tue	44	—	unknown	04:10–05:55 (good, 1.75 h)	50.1° 07:55	11.38	46%	151.4°
2046-12-05 Wed	45	—	unknown	04:05–05:55 (good, 1.83 h)	50.1° 07:50	11.4	56%	162.1°
2046-12-06 Thu	46	—	unknown	04:00–05:55 (good, 1.92 h)	50.1° 07:50	11.41	65%	169.8°
2046-12-07 Fri	49	—	unknown	03:55–06:00 (good, 2.08 h)	50.1° 07:45	11.42	74%	167.2°
2046-12-08 Sat	50	—	unknown	03:55–06:00 (good, 2.08 h)	50.1° 07:40	11.43	81%	157.5°
2046-12-09 Sun	51	—	unknown	03:55–06:00 (good, 2.08 h)	50.1° 07:35	11.44	88%	146.3°
2046-12-10 Mon	51	—	unknown	03:55–06:00 (good, 2.08 h)	50.1° 07:30	11.45	94%	134.6°
2046-12-11 Tue	46	—	unknown	03:55–06:00 (good, 2.08 h)	50.1° 07:30	11.46	98%	122.5°
2046-12-12 Wed	40	—	unknown	04:00–06:00 (good, 2.0 h)	50.1° 07:25	11.47	100%	110.1°
2046-12-13 Thu	34	—	unknown	04:25–06:00 (good, 1.58 h)	50.1° 07:20	11.48	100%	97.5°
2046-12-14 Fri	28	—	unknown	05:35–06:05 (good, 0.5 h)	50.1° 07:15	11.49	98%	84.6°
2046-12-15 Sat	22	—	unknown	03:20–06:05 (marginal, 2.75 h)	50.1° 07:10	11.49	93%	71.5°
2046-12-16 Sun	19	—	unknown	03:20–06:05 (marginal, 2.75 h)	50.1° 07:10	11.5	87%	58.2°
2046-12-17 Mon	17	—	unknown	03:20–06:05 (marginal, 2.75 h)	50.1° 07:05	11.5	78%	44.9°
2046-12-18 Tue	19	—	unknown	03:10–06:05 (marginal, 2.92 h)	50.1° 07:00	11.5	69%	31.6°
2046-12-19 Wed	26	—	unknown	02:50–06:05 (marginal, 3.25 h)	50.1° 06:55	11.51	58%	18.9°
2046-12-20 Thu	35	—	unknown	04:05–06:05 (good, 2.0 h)	50.1° 06:55	11.51	46%	9.9°
2046-12-21 Fri	46	—	unknown	03:20–06:05 (good, 2.75 h)	50.1° 06:50	11.51	35%	15.3°
2046-12-22 Sat	59	—	unknown	03:00–06:10 (good, 3.17 h)	50.1° 06:45	11.51	25%	27.8°
2046-12-23 Sun	71	—	unknown	02:55–06:10 (good, 3.25 h)	50.1° 06:40	11.51	15%	41.5°
2046-12-24 Mon	78	—	unknown	02:50–06:10 (good, 3.33 h)	50.1° 06:35	11.5	8%	55.4°
2046-12-25 Tue	81	—	unknown	02:45–06:10 (good, 3.42 h)	50.1° 06:35	11.5	3%	69.3°
2046-12-26 Wed	82	—	unknown	02:45–06:10 (good, 3.42 h)	50.1° 06:30	11.5	0%	83.1°
2046-12-27 Thu	84	—	unknown	02:40–06:10 (good, 3.5 h)	50.1° 06:25	11.49	0%	96.7°
2046-12-28 Fri	86	—	unknown	02:35–06:10 (good, 3.58 h)	50.1° 06:20	11.48	3%	109.9°
2046-12-29 Sat	87	—	unknown	02:30–06:10 (good, 3.67 h)	50.1° 06:15	11.48	7%	122.8°
2046-12-30 Sun	88	—	unknown	02:25–06:10 (good, 3.75 h)	50.1° 06:15	11.47	13%	135.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-12-01&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.