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: 12-24 (66), 12-11 (55), 12-23 (55), 12-10 (54), 12-12 (54) — by astronomy; check the weather when the night is within four days.

2035-11-25astronomy score per night — click a bar for that night2035-12-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-11-25 Sun	24	—	unknown	04:50–05:45 (good, 0.92 h)	50.2° 08:30	11.21	15%	12.9°
2035-11-26 Mon	27	—	unknown	04:40–05:50 (good, 1.17 h)	50.2° 08:30	11.23	8%	25.5°
2035-11-27 Tue	31	—	unknown	04:35–05:50 (good, 1.25 h)	50.2° 08:25	11.25	4%	38.0°
2035-11-28 Wed	33	—	unknown	04:35–05:50 (good, 1.25 h)	50.2° 08:20	11.27	1%	50.4°
2035-11-29 Thu	35	—	unknown	04:30–05:50 (good, 1.33 h)	50.2° 08:15	11.29	0%	62.6°
2035-11-30 Fri	36	—	unknown	04:25–05:50 (good, 1.42 h)	50.2° 08:10	11.31	1%	74.6°
2035-12-01 Sat	38	—	unknown	04:20–05:55 (good, 1.58 h)	50.2° 08:10	11.33	4%	86.5°
2035-12-02 Sun	39	—	unknown	04:20–05:55 (good, 1.58 h)	50.2° 08:05	11.34	9%	98.4°
2035-12-03 Mon	42	—	unknown	04:15–05:55 (good, 1.67 h)	50.2° 08:00	11.36	15%	110.2°
2035-12-04 Tue	43	—	unknown	04:10–05:55 (good, 1.75 h)	50.2° 07:55	11.38	22%	122.0°
2035-12-05 Wed	45	—	unknown	04:05–05:55 (good, 1.83 h)	50.2° 07:55	11.39	30%	133.9°
2035-12-06 Thu	46	—	unknown	04:00–05:55 (good, 1.92 h)	50.2° 07:50	11.4	39%	145.9°
2035-12-07 Fri	49	—	unknown	04:00–06:00 (good, 2.0 h)	50.2° 07:45	11.42	49%	158.1°
2035-12-08 Sat	50	—	unknown	03:55–06:00 (good, 2.08 h)	50.2° 07:40	11.43	59%	170.6°
2035-12-09 Sun	53	—	unknown	03:50–06:00 (good, 2.17 h)	50.2° 07:35	11.44	69%	175.9°
2035-12-10 Mon	54	—	unknown	03:45–06:00 (good, 2.25 h)	50.2° 07:35	11.45	78%	162.8°
2035-12-11 Tue	55	—	unknown	03:50–06:00 (good, 2.17 h)	50.2° 07:30	11.46	87%	149.0°
2035-12-12 Wed	54	—	unknown	03:45–06:00 (good, 2.25 h)	50.2° 07:25	11.47	93%	134.6°
2035-12-13 Thu	49	—	unknown	03:45–06:00 (good, 2.25 h)	50.2° 07:20	11.48	98%	119.9°
2035-12-14 Fri	41	—	unknown	03:55–06:05 (good, 2.17 h)	50.2° 07:15	11.48	100%	104.8°
2035-12-15 Sat	32	—	unknown	04:55–06:05 (good, 1.17 h)	50.2° 07:15	11.49	99%	89.6°
2035-12-16 Sun	25	—	unknown	03:15–06:05 (marginal, 2.83 h)	50.2° 07:10	11.5	94%	74.4°
2035-12-17 Mon	19	—	unknown	03:15–06:05 (marginal, 2.83 h)	50.2° 07:05	11.5	88%	59.4°
2035-12-18 Tue	17	—	unknown	03:15–06:05 (marginal, 2.83 h)	50.2° 07:00	11.5	79%	44.8°
2035-12-19 Wed	18	—	unknown	03:05–06:05 (marginal, 3.0 h)	50.2° 07:00	11.51	69%	30.5°
2035-12-20 Thu	25	—	unknown	02:50–06:05 (marginal, 3.25 h)	50.2° 06:55	11.51	58%	16.6°
2035-12-21 Fri	34	—	unknown	04:45–06:05 (good, 1.33 h)	50.2° 06:50	11.51	47%	3.5°
2035-12-22 Sat	44	—	unknown	03:20–06:05 (good, 2.75 h)	50.2° 06:45	11.51	37%	10.1°
2035-12-23 Sun	55	—	unknown	03:05–06:10 (good, 3.08 h)	50.2° 06:40	11.51	28%	22.7°
2035-12-24 Mon	66	—	unknown	02:50–06:10 (good, 3.33 h)	50.2° 06:40	11.5	19%	35.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-11-25&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.