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: 01-03 (93), 01-04 (93), 01-05 (93), 01-06 (93), 01-07 (93) — by astronomy; check the weather when the night is within four days.

2045-12-19astronomy score per night — click a bar for that night2046-01-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-12-19 Tue	69	—	unknown	03:15–06:05 (good, 2.83 h)	50.1° 06:55	11.51	81%	147.8°
2045-12-20 Wed	69	—	unknown	03:15–06:05 (good, 2.83 h)	50.1° 06:50	11.51	88%	135.2°
2045-12-21 Thu	62	—	unknown	03:10–06:05 (good, 2.92 h)	50.1° 06:50	11.51	94%	122.0°
2045-12-22 Fri	54	—	unknown	03:20–06:10 (good, 2.83 h)	50.1° 06:45	11.51	98%	108.4°
2045-12-23 Sat	43	—	unknown	04:05–06:10 (good, 2.08 h)	50.1° 06:40	11.5	100%	94.4°
2045-12-24 Sun	33	—	unknown	05:35–06:10 (good, 0.58 h)	50.1° 06:35	11.5	99%	80.2°
2045-12-25 Mon	25	—	unknown	02:45–06:10 (marginal, 3.42 h)	50.1° 06:30	11.5	95%	65.8°
2045-12-26 Tue	20	—	unknown	02:50–06:10 (marginal, 3.33 h)	50.1° 06:30	11.49	89%	51.4°
2045-12-27 Wed	18	—	unknown	02:45–06:10 (marginal, 3.42 h)	50.1° 06:25	11.49	80%	37.1°
2045-12-28 Thu	23	—	unknown	02:25–06:10 (marginal, 3.75 h)	50.1° 06:20	11.48	70%	23.4°
2045-12-29 Fri	32	—	unknown	02:10–06:10 (marginal, 4.0 h)	50.1° 06:15	11.48	59%	11.6°
2045-12-30 Sat	44	—	unknown	03:05–06:10 (good, 3.08 h)	50.1° 06:15	11.47	48%	11.0°
2045-12-31 Sun	57	—	unknown	02:40–06:10 (good, 3.5 h)	50.1° 06:10	11.46	37%	22.0°
2046-01-01 Mon	75	—	unknown	02:20–06:10 (good, 3.83 h)	50.1° 06:05	11.45	27%	34.8°
2046-01-02 Tue	87	—	unknown	02:15–06:10 (good, 3.92 h)	50.1° 06:00	11.44	18%	47.7°
2046-01-03 Wed	93	—	unknown	02:10–06:10 (good, 4.0 h)	50.1° 05:55	11.43	11%	60.6°
2046-01-04 Thu	93	—	unknown	02:05–06:10 (good, 4.08 h)	50.1° 05:55	11.41	5%	73.3°
2046-01-05 Fri	93	—	unknown	02:00–06:10 (good, 4.17 h)	50.1° 05:50	11.4	2%	85.9°
2046-01-06 Sat	93	—	unknown	02:00–06:10 (good, 4.17 h)	50.1° 05:45	11.39	0%	98.2°
2046-01-07 Sun	93	—	unknown	01:55–06:10 (good, 4.25 h)	50.1° 05:40	11.37	1%	110.4°
2046-01-08 Mon	93	—	unknown	01:50–06:10 (good, 4.33 h)	50.1° 05:35	11.36	3%	122.4°
2046-01-09 Tue	93	—	unknown	01:45–06:10 (good, 4.42 h)	50.1° 05:35	11.34	7%	134.2°
2046-01-10 Wed	93	—	unknown	01:45–06:10 (good, 4.42 h)	50.1° 05:30	11.32	12%	145.7°
2046-01-11 Thu	93	—	unknown	01:40–06:10 (good, 4.5 h)	50.1° 05:25	11.3	19%	156.9°
2046-01-12 Fri	93	—	unknown	01:35–06:10 (good, 4.58 h)	50.1° 05:20	11.28	27%	166.9°
2046-01-13 Sat	93	—	unknown	01:30–06:10 (good, 4.67 h)	50.1° 05:15	11.26	36%	170.8°
2046-01-14 Sun	93	—	unknown	01:25–06:10 (good, 4.75 h)	50.1° 05:15	11.24	45%	163.2°
2046-01-15 Mon	93	—	unknown	01:25–06:10 (good, 4.75 h)	50.1° 05:10	11.22	55%	152.1°
2046-01-16 Tue	93	—	unknown	01:25–06:10 (good, 4.75 h)	50.1° 05:05	11.2	65%	140.1°
2046-01-17 Wed	93	—	unknown	01:25–06:10 (good, 4.75 h)	50.1° 05:00	11.18	75%	127.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-12-19&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.