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 North America Nebula: 12-12 (95), 12-13 (95), 12-11 (94), 12-14 (93), 12-10 (91) — by astronomy; check the weather when the night is within four days.

2041-12-06astronomy score per night — click a bar for that night2042-01-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-12-06 Fri	49	—	unknown	18:35–20:15 (good, 1.67 h)	87.2° 16:20	11.41	99%	85.4°
2041-12-07 Sat	56	—	unknown	18:35–20:55 (good, 2.33 h)	87.2° 16:15	11.42	100%	91.9°
2041-12-08 Sun	64	—	unknown	18:35–21:45 (good, 3.17 h)	87.2° 16:10	11.44	98%	98.1°
2041-12-09 Mon	73	—	unknown	18:35–22:00 (good, 3.42 h)	87.2° 16:05	11.45	94%	103.9°
2041-12-10 Tue	91	—	unknown	18:35–22:05 (good, 3.5 h)	87.2° 16:05	11.46	89%	109.0°
2041-12-11 Wed	94	—	unknown	18:35–22:05 (good, 3.5 h)	87.2° 16:00	11.47	82%	113.1°
2041-12-12 Thu	95	—	unknown	18:35–22:05 (good, 3.5 h)	87.2° 15:55	11.47	74%	116.1°
2041-12-13 Fri	95	—	unknown	18:35–22:10 (good, 3.58 h)	87.2° 15:50	11.48	65%	117.9°
2041-12-14 Sat	93	—	unknown	18:35–22:05 (good, 3.5 h)	87.2° 15:45	11.49	56%	118.4°
2041-12-15 Sun	91	—	unknown	18:35–22:05 (good, 3.5 h)	87.2° 15:45	11.49	47%	117.6°
2041-12-16 Mon	89	—	unknown	18:35–22:00 (good, 3.42 h)	87.2° 15:40	11.5	37%	115.5°
2041-12-17 Tue	87	—	unknown	18:35–21:55 (good, 3.33 h)	87.2° 15:35	11.5	28%	112.2°
2041-12-18 Wed	85	—	unknown	18:35–21:50 (good, 3.25 h)	87.2° 15:30	11.5	20%	108.0°
2041-12-19 Thu	83	—	unknown	18:35–21:45 (good, 3.17 h)	87.2° 15:25	11.51	13%	102.9°
2041-12-20 Fri	81	—	unknown	18:35–21:45 (good, 3.17 h)	87.2° 15:25	11.51	7%	97.1°
2041-12-21 Sat	78	—	unknown	18:35–21:40 (good, 3.08 h)	87.2° 15:20	11.51	2%	90.9°
2041-12-22 Sun	76	—	unknown	18:35–21:35 (good, 3.0 h)	87.2° 15:15	11.51	0%	84.5°
2041-12-23 Mon	73	—	unknown	18:40–21:30 (good, 2.83 h)	87.2° 15:10	11.51	1%	78.1°
2041-12-24 Tue	71	—	unknown	18:40–21:30 (good, 2.83 h)	87.2° 15:10	11.5	3%	72.3°
2041-12-25 Wed	67	—	unknown	18:40–21:25 (good, 2.75 h)	87.2° 15:05	11.5	9%	67.4°
2041-12-26 Thu	61	—	unknown	18:40–21:20 (good, 2.67 h)	87.2° 15:00	11.49	16%	63.7°
2041-12-27 Fri	53	—	unknown	18:40–21:05 (good, 2.42 h)	87.2° 14:55	11.49	26%	61.8°
2041-12-28 Sat	45	—	unknown	18:40–20:55 (good, 2.25 h)	87.2° 14:50	11.48	36%	61.7°
2041-12-29 Sun	37	—	unknown	18:40–20:40 (good, 2.0 h)	87.2° 14:50	11.48	48%	63.5°
2041-12-30 Mon	31	—	unknown	18:40–20:00 (good, 1.33 h)	87.2° 14:45	11.47	59%	66.9°
2041-12-31 Tue	26	—	unknown	18:45–19:05 (good, 0.33 h)	87.2° 14:40	11.46	70%	71.6°
2042-01-01 Wed	24	—	unknown	18:10–21:20 (marginal, 3.17 h)	87.2° 14:35	11.45	79%	77.3°
2042-01-02 Thu	23	—	unknown	18:45–18:50 (good, 0.08 h)	87.2° 14:30	11.44	87%	83.4°
2042-01-03 Fri	25	—	unknown	18:45–19:10 (good, 0.42 h)	87.2° 14:30	11.43	94%	89.8°
2042-01-04 Sat	26	—	unknown	18:45–19:40 (good, 0.92 h)	87.2° 14:25	11.41	98%	96.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-12-06&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.