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: 01-06 (93), 01-07 (93), 01-08 (93), 01-09 (93), 01-10 (93) — by astronomy; check the weather when the night is within four days.

2034-12-22astronomy score per night — click a bar for that night2035-01-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-12-22 Fri	72	—	unknown	03:05–06:10 (good, 3.08 h)	50.2° 06:45	11.51	91%	129.5°
2034-12-23 Sat	62	—	unknown	03:10–06:10 (good, 3.0 h)	50.2° 06:40	11.51	97%	114.5°
2034-12-24 Sun	50	—	unknown	03:25–06:10 (good, 2.75 h)	50.2° 06:35	11.5	100%	99.3°
2034-12-25 Mon	39	—	unknown	04:50–06:10 (good, 1.33 h)	50.2° 06:35	11.5	99%	84.2°
2034-12-26 Tue	29	—	unknown	02:40–06:10 (marginal, 3.5 h)	50.2° 06:30	11.5	96%	69.4°
2034-12-27 Wed	22	—	unknown	02:45–06:10 (marginal, 3.42 h)	50.2° 06:25	11.49	91%	54.9°
2034-12-28 Thu	19	—	unknown	02:45–06:10 (marginal, 3.42 h)	50.2° 06:20	11.48	83%	40.8°
2034-12-29 Fri	20	—	unknown	02:30–06:10 (marginal, 3.67 h)	50.2° 06:15	11.48	74%	27.3°
2034-12-30 Sat	27	—	unknown	02:10–06:10 (marginal, 4.0 h)	50.2° 06:15	11.47	65%	14.4°
2034-12-31 Sun	36	—	unknown	01:55–06:10 (marginal, 4.25 h)	50.2° 06:10	11.46	55%	3.4°
2035-01-01 Mon	47	—	unknown	02:45–06:10 (good, 3.42 h)	50.2° 06:05	11.45	45%	11.5°
2035-01-02 Tue	59	—	unknown	02:30–06:10 (good, 3.67 h)	50.2° 06:00	11.44	36%	23.3°
2035-01-03 Wed	74	—	unknown	02:10–06:10 (good, 4.0 h)	50.2° 06:00	11.43	27%	35.2°
2035-01-04 Thu	86	—	unknown	02:05–06:10 (good, 4.08 h)	50.2° 05:55	11.42	19%	47.0°
2035-01-05 Fri	92	—	unknown	02:05–06:10 (good, 4.08 h)	50.2° 05:50	11.4	12%	58.7°
2035-01-06 Sat	93	—	unknown	02:00–06:10 (good, 4.17 h)	50.2° 05:45	11.39	7%	70.5°
2035-01-07 Sun	93	—	unknown	01:55–06:10 (good, 4.25 h)	50.2° 05:40	11.38	3%	82.4°
2035-01-08 Mon	93	—	unknown	01:50–06:10 (good, 4.33 h)	50.2° 05:40	11.36	1%	94.5°
2035-01-09 Tue	93	—	unknown	01:45–06:10 (good, 4.42 h)	50.2° 05:35	11.34	0%	106.6°
2035-01-10 Wed	93	—	unknown	01:45–06:10 (good, 4.42 h)	50.2° 05:30	11.33	2%	118.9°
2035-01-11 Thu	93	—	unknown	01:40–06:10 (good, 4.5 h)	50.2° 05:25	11.31	5%	131.4°
2035-01-12 Fri	93	—	unknown	01:35–06:10 (good, 4.58 h)	50.2° 05:20	11.29	11%	144.1°
2035-01-13 Sat	93	—	unknown	01:30–06:10 (good, 4.67 h)	50.2° 05:20	11.27	18%	156.9°
2035-01-14 Sun	93	—	unknown	01:25–06:10 (good, 4.75 h)	50.2° 05:15	11.25	26%	169.8°
2035-01-15 Mon	93	—	unknown	01:25–06:10 (good, 4.75 h)	50.2° 05:10	11.23	36%	175.4°
2035-01-16 Tue	93	—	unknown	01:20–06:10 (good, 4.83 h)	50.2° 05:05	11.21	47%	162.6°
2035-01-17 Wed	93	—	unknown	01:20–06:10 (good, 4.83 h)	50.2° 05:00	11.18	58%	148.8°
2035-01-18 Thu	93	—	unknown	01:20–06:10 (good, 4.83 h)	50.2° 05:00	11.16	69%	134.6°
2035-01-19 Fri	93	—	unknown	01:15–06:10 (good, 4.92 h)	50.2° 04:55	11.14	80%	120.2°
2035-01-20 Sat	93	—	unknown	01:25–06:10 (good, 4.75 h)	50.2° 04:50	11.11	88%	105.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-12-22&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.