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: 12-27 (85), 12-28 (85), 01-10 (85), 12-26 (84), 12-29 (84) — by astronomy; check the weather when the night is within four days.

2036-12-12astronomy score per night — click a bar for that night2037-01-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-12-12 Fri	44	—	unknown	03:45–06:00 (good, 2.25 h)	50.2° 07:20	11.48	23%	18.1°
2036-12-13 Sat	53	—	unknown	03:30–06:05 (good, 2.58 h)	50.2° 07:20	11.48	15%	31.6°
2036-12-14 Sun	59	—	unknown	03:25–06:05 (good, 2.67 h)	50.2° 07:15	11.49	8%	44.9°
2036-12-15 Mon	65	—	unknown	03:25–06:05 (good, 2.67 h)	50.2° 07:10	11.49	3%	58.1°
2036-12-16 Tue	66	—	unknown	03:20–06:05 (good, 2.75 h)	50.2° 07:05	11.5	1%	71.0°
2036-12-17 Wed	68	—	unknown	03:15–06:05 (good, 2.83 h)	50.2° 07:00	11.5	0%	83.7°
2036-12-18 Thu	69	—	unknown	03:10–06:05 (good, 2.92 h)	50.2° 07:00	11.5	2%	96.2°
2036-12-19 Fri	71	—	unknown	03:10–06:05 (good, 2.92 h)	50.2° 06:55	11.51	5%	108.4°
2036-12-20 Sat	73	—	unknown	03:05–06:05 (good, 3.0 h)	50.2° 06:50	11.51	10%	120.5°
2036-12-21 Sun	74	—	unknown	03:00–06:05 (good, 3.08 h)	50.2° 06:45	11.51	16%	132.5°
2036-12-22 Mon	76	—	unknown	02:55–06:10 (good, 3.25 h)	50.2° 06:45	11.51	24%	144.3°
2036-12-23 Tue	78	—	unknown	02:50–06:10 (good, 3.33 h)	50.2° 06:40	11.5	32%	156.2°
2036-12-24 Wed	80	—	unknown	02:50–06:10 (good, 3.33 h)	50.2° 06:35	11.5	42%	168.0°
2036-12-25 Thu	82	—	unknown	02:45–06:10 (good, 3.42 h)	50.2° 06:30	11.5	51%	179.6°
2036-12-26 Fri	84	—	unknown	02:40–06:10 (good, 3.5 h)	50.2° 06:25	11.49	61%	167.8°
2036-12-27 Sat	85	—	unknown	02:35–06:10 (good, 3.58 h)	50.2° 06:25	11.49	70%	155.3°
2036-12-28 Sun	85	—	unknown	02:40–06:10 (good, 3.5 h)	50.2° 06:20	11.48	79%	142.4°
2036-12-29 Mon	84	—	unknown	02:35–06:10 (good, 3.58 h)	50.2° 06:15	11.47	87%	129.1°
2036-12-30 Tue	81	—	unknown	02:40–06:10 (good, 3.5 h)	50.2° 06:10	11.47	94%	115.3°
2036-12-31 Wed	61	—	unknown	02:50–06:10 (good, 3.33 h)	50.2° 06:05	11.46	98%	101.2°
2037-01-01 Thu	47	—	unknown	04:10–06:10 (good, 2.0 h)	50.2° 06:05	11.45	100%	86.6°
2037-01-02 Fri	35	—	unknown	02:10–06:10 (marginal, 4.0 h)	50.2° 06:00	11.44	99%	71.9°
2037-01-03 Sat	25	—	unknown	02:20–06:10 (marginal, 3.83 h)	50.2° 05:55	11.42	95%	57.0°
2037-01-04 Sun	19	—	unknown	02:25–06:10 (marginal, 3.75 h)	50.2° 05:50	11.41	89%	42.1°
2037-01-05 Mon	18	—	unknown	02:15–06:10 (marginal, 3.92 h)	50.2° 05:50	11.4	80%	27.4°
2037-01-06 Tue	25	—	unknown	01:45–06:10 (marginal, 4.42 h)	50.2° 05:45	11.38	70%	12.9°
2037-01-07 Wed	36	—	unknown	01:30–06:10 (marginal, 4.67 h)	50.2° 05:40	11.37	59%	1.3°
2037-01-08 Thu	50	—	unknown	02:15–06:10 (good, 3.92 h)	50.2° 05:35	11.35	48%	15.2°
2037-01-09 Fri	66	—	unknown	01:45–06:10 (good, 4.42 h)	50.2° 05:30	11.34	37%	28.7°
2037-01-10 Sat	85	—	unknown	01:40–06:10 (good, 4.5 h)	50.2° 05:30	11.32	27%	42.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-12-12&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.