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: 12-20 (72), 12-21 (72), 12-22 (72), 12-19 (70), 12-18 (69) — by astronomy; check the weather when the night is within four days.

2034-12-04astronomy score per night — click a bar for that night2035-01-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-12-04 Mon	30	—	unknown	04:25–05:55 (good, 1.5 h)	50.2° 07:55	11.38	28%	4.0°
2034-12-05 Tue	36	—	unknown	04:15–05:55 (good, 1.67 h)	50.2° 07:50	11.39	20%	14.7°
2034-12-06 Wed	41	—	unknown	04:00–05:55 (good, 1.92 h)	50.2° 07:50	11.41	13%	26.4°
2034-12-07 Thu	47	—	unknown	03:55–06:00 (good, 2.08 h)	50.2° 07:45	11.42	8%	38.2°
2034-12-08 Fri	50	—	unknown	03:55–06:00 (good, 2.08 h)	50.2° 07:40	11.43	3%	50.0°
2034-12-09 Sat	53	—	unknown	03:50–06:00 (good, 2.17 h)	50.2° 07:35	11.44	1%	61.8°
2034-12-10 Sun	55	—	unknown	03:45–06:00 (good, 2.25 h)	50.2° 07:30	11.45	0%	73.6°
2034-12-11 Mon	56	—	unknown	03:40–06:00 (good, 2.33 h)	50.2° 07:30	11.46	1%	85.5°
2034-12-12 Tue	57	—	unknown	03:35–06:00 (good, 2.42 h)	50.2° 07:25	11.47	4%	97.5°
2034-12-13 Wed	59	—	unknown	03:35–06:00 (good, 2.42 h)	50.2° 07:20	11.48	9%	109.6°
2034-12-14 Thu	62	—	unknown	03:30–06:05 (good, 2.58 h)	50.2° 07:15	11.49	15%	121.8°
2034-12-15 Fri	64	—	unknown	03:25–06:05 (good, 2.67 h)	50.2° 07:10	11.49	22%	134.2°
2034-12-16 Sat	65	—	unknown	03:20–06:05 (good, 2.75 h)	50.2° 07:10	11.5	31%	146.8°
2034-12-17 Sun	67	—	unknown	03:20–06:05 (good, 2.75 h)	50.2° 07:05	11.5	41%	159.7°
2034-12-18 Mon	69	—	unknown	03:15–06:05 (good, 2.83 h)	50.2° 07:00	11.5	52%	172.5°
2034-12-19 Tue	70	—	unknown	03:10–06:05 (good, 2.92 h)	50.2° 06:55	11.51	63%	172.4°
2034-12-20 Wed	72	—	unknown	03:05–06:05 (good, 3.0 h)	50.2° 06:55	11.51	74%	158.7°
2034-12-21 Thu	72	—	unknown	03:10–06:05 (good, 2.92 h)	50.2° 06:50	11.51	83%	144.3°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-12-04&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.