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), 01-02 (87) — by astronomy; check the weather when the night is within four days.

2045-12-08astronomy score per night — click a bar for that night2046-01-06

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-12-08 Fri	51	—	unknown	03:50–06:00 (good, 2.17 h)	50.1° 07:40	11.44	0%	77.0°
2045-12-09 Sat	53	—	unknown	03:50–06:00 (good, 2.17 h)	50.1° 07:35	11.45	2%	89.7°
2045-12-10 Sun	55	—	unknown	03:45–06:00 (good, 2.25 h)	50.1° 07:30	11.46	6%	102.1°
2045-12-11 Mon	56	—	unknown	03:40–06:00 (good, 2.33 h)	50.1° 07:25	11.47	12%	114.2°
2045-12-12 Tue	57	—	unknown	03:35–06:00 (good, 2.42 h)	50.1° 07:25	11.47	18%	126.1°
2045-12-13 Wed	60	—	unknown	03:35–06:05 (good, 2.5 h)	50.1° 07:20	11.48	26%	137.8°
2045-12-14 Thu	62	—	unknown	03:30–06:05 (good, 2.58 h)	50.1° 07:15	11.49	35%	149.2°
2045-12-15 Fri	64	—	unknown	03:25–06:05 (good, 2.67 h)	50.1° 07:10	11.49	44%	160.2°
2045-12-16 Sat	65	—	unknown	03:20–06:05 (good, 2.75 h)	50.1° 07:10	11.5	54%	169.5°
2045-12-17 Sun	67	—	unknown	03:15–06:05 (good, 2.83 h)	50.1° 07:05	11.5	63%	169.3°
2045-12-18 Mon	69	—	unknown	03:15–06:05 (good, 2.83 h)	50.1° 07:00	11.5	72%	159.6°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-12-08&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.