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.

2046-12-22astronomy score per night — click a bar for that night2047-01-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2046-12-31 Mon	90	—	unknown	02:25–06:10 (good, 3.75 h)	50.1° 06:10	11.46	20%	147.3°
2047-01-01 Tue	91	—	unknown	02:20–06:10 (good, 3.83 h)	50.1° 06:05	11.45	29%	158.5°
2047-01-02 Wed	93	—	unknown	02:15–06:10 (good, 3.92 h)	50.1° 06:00	11.44	38%	167.9°
2047-01-03 Thu	93	—	unknown	02:10–06:10 (good, 4.0 h)	50.1° 06:00	11.43	47%	169.2°
2047-01-04 Fri	93	—	unknown	02:05–06:10 (good, 4.08 h)	50.1° 05:55	11.42	57%	160.9°
2047-01-05 Sat	93	—	unknown	02:10–06:10 (good, 4.0 h)	50.1° 05:50	11.4	66%	150.2°
2047-01-06 Sun	93	—	unknown	02:05–06:10 (good, 4.08 h)	50.1° 05:45	11.39	75%	138.7°
2047-01-07 Mon	93	—	unknown	02:05–06:10 (good, 4.08 h)	50.1° 05:40	11.37	83%	126.8°
2047-01-08 Tue	92	—	unknown	02:05–06:10 (good, 4.08 h)	50.1° 05:40	11.36	90%	114.6°
2047-01-09 Wed	71	—	unknown	02:15–06:10 (good, 3.92 h)	50.1° 05:35	11.34	95%	102.0°
2047-01-10 Thu	58	—	unknown	03:20–06:10 (good, 2.83 h)	50.1° 05:30	11.33	98%	89.0°
2047-01-11 Fri	44	—	unknown	05:05–06:10 (good, 1.08 h)	50.1° 05:25	11.31	100%	75.8°
2047-01-12 Sat	32	—	unknown	01:45–06:10 (marginal, 4.42 h)	50.1° 05:20	11.29	99%	62.3°
2047-01-13 Sun	24	—	unknown	01:55–06:10 (marginal, 4.25 h)	50.1° 05:20	11.27	96%	48.6°
2047-01-14 Mon	20	—	unknown	01:55–06:10 (marginal, 4.25 h)	50.1° 05:15	11.25	90%	35.0°
2047-01-15 Tue	23	—	unknown	01:30–06:10 (marginal, 4.67 h)	50.1° 05:10	11.23	82%	21.8°
2047-01-16 Wed	32	—	unknown	01:05–06:10 (marginal, 5.08 h)	50.1° 05:05	11.21	72%	11.1°
2047-01-17 Thu	44	—	unknown	00:50–06:10 (marginal, 5.33 h)	50.1° 05:05	11.18	61%	13.2°
2047-01-18 Fri	60	—	unknown	01:35–06:10 (good, 4.58 h)	50.1° 05:00	11.16	50%	24.9°
2047-01-19 Sat	85	—	unknown	01:10–06:10 (good, 5.0 h)	50.1° 04:55	11.13	39%	38.2°
2047-01-20 Sun	91	—	unknown	01:05–06:10 (good, 5.08 h)	50.1° 04:50	11.11	28%	51.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-12-22&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.