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: 12-09 (51), 12-10 (51), 12-08 (50), 12-07 (49), 12-06 (46) — by astronomy; check the weather when the night is within four days.

2046-11-18astronomy score per night — click a bar for that night2046-12-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-11-18 Sun	6	—	unknown	04:55–05:40 (marginal, 0.75 h)	50.1° 09:00	11.05	74%	68.4°
2046-11-19 Mon	7	—	unknown	04:50–05:40 (marginal, 0.83 h)	50.1° 08:55	11.07	64%	55.3°
2046-11-20 Tue	8	—	unknown	04:45–05:40 (marginal, 0.92 h)	50.1° 08:50	11.1	54%	42.0°
2046-11-21 Wed	11	—	unknown	04:35–05:45 (marginal, 1.17 h)	50.1° 08:45	11.12	43%	28.7°
2046-11-22 Thu	15	—	unknown	05:20–05:45 (good, 0.42 h)	50.1° 08:45	11.15	32%	16.1°
2046-11-23 Fri	19	—	unknown	05:05–05:45 (good, 0.67 h)	50.1° 08:40	11.17	21%	9.6°
2046-11-24 Sat	23	—	unknown	04:55–05:45 (good, 0.83 h)	50.1° 08:35	11.19	12%	18.6°
2046-11-25 Sun	28	—	unknown	04:45–05:45 (good, 1.0 h)	50.1° 08:30	11.22	6%	32.1°
2046-11-26 Mon	30	—	unknown	04:40–05:50 (good, 1.17 h)	50.1° 08:25	11.24	2%	46.4°
2046-11-27 Tue	31	—	unknown	04:35–05:50 (good, 1.25 h)	50.1° 08:25	11.26	0%	60.7°
2046-11-28 Wed	33	—	unknown	04:35–05:50 (good, 1.25 h)	50.1° 08:20	11.28	1%	74.8°
2046-11-29 Thu	35	—	unknown	04:30–05:50 (good, 1.33 h)	50.1° 08:15	11.3	5%	88.7°
2046-11-30 Fri	36	—	unknown	04:25–05:50 (good, 1.42 h)	50.1° 08:10	11.32	11%	102.1°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-11-18&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.