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: 12-18 (84), 12-19 (82), 12-20 (80), 12-21 (78), 12-22 (72) — by astronomy; check the weather when the night is within four days.

2044-12-18astronomy score per night — click a bar for that night2045-01-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-12-18 Sun	84	—	unknown	18:35–21:50 (good, 3.25 h)	87.2° 15:30	11.51	0%	86.9°
2044-12-19 Mon	82	—	unknown	18:35–21:45 (good, 3.17 h)	87.2° 15:25	11.51	0%	80.5°
2044-12-20 Tue	80	—	unknown	18:35–21:45 (good, 3.17 h)	87.2° 15:20	11.51	2%	74.4°
2044-12-21 Wed	78	—	unknown	18:35–21:40 (good, 3.08 h)	87.2° 15:20	11.51	6%	68.8°
2044-12-22 Thu	72	—	unknown	18:35–21:35 (good, 3.0 h)	87.2° 15:15	11.51	11%	63.9°
2044-12-23 Fri	65	—	unknown	18:40–21:30 (good, 2.83 h)	87.2° 15:10	11.5	17%	60.1°
2044-12-24 Sat	57	—	unknown	18:40–21:20 (good, 2.67 h)	87.2° 15:05	11.5	25%	57.6°
2044-12-25 Sun	49	—	unknown	18:40–21:05 (good, 2.42 h)	87.2° 15:05	11.5	34%	56.6°
2044-12-26 Mon	41	—	unknown	18:40–20:55 (good, 2.25 h)	87.2° 15:00	11.49	44%	57.3°
2044-12-27 Tue	34	—	unknown	18:40–20:20 (good, 1.67 h)	87.2° 14:55	11.49	54%	59.8°
2044-12-28 Wed	28	—	unknown	18:40–19:05 (good, 0.42 h)	87.2° 14:50	11.48	64%	63.8°
2044-12-29 Thu	25	—	unknown	18:40–21:30 (marginal, 2.83 h)	87.2° 14:45	11.47	74%	69.4°
2044-12-30 Fri	23	—	unknown	18:45–21:25 (marginal, 2.67 h)	87.2° 14:45	11.47	83%	76.1°
2044-12-31 Sat	24	—	unknown	18:45–18:50 (good, 0.08 h)	87.2° 14:40	11.46	91%	83.7°
2045-01-01 Sun	27	—	unknown	18:45–19:25 (good, 0.67 h)	87.2° 14:35	11.45	96%	91.9°
2045-01-02 Mon	31	—	unknown	18:45–20:15 (good, 1.5 h)	87.2° 14:30	11.43	100%	100.1°
2045-01-03 Tue	36	—	unknown	18:45–20:25 (good, 1.67 h)	87.2° 14:25	11.42	100%	107.8°
2045-01-04 Wed	39	—	unknown	18:45–20:30 (good, 1.75 h)	87.2° 14:25	11.41	96%	114.6°
2045-01-05 Thu	46	—	unknown	18:45–20:30 (good, 1.75 h)	87.2° 14:20	11.4	91%	119.7°
2045-01-06 Fri	44	—	unknown	18:50–20:35 (good, 1.75 h)	87.2° 14:15	11.38	83%	122.7°
2045-01-07 Sat	43	—	unknown	18:50–20:30 (good, 1.67 h)	87.2° 14:10	11.37	73%	123.4°
2045-01-08 Sun	42	—	unknown	18:50–20:30 (good, 1.67 h)	87.2° 14:10	11.35	63%	121.8°
2045-01-09 Mon	40	—	unknown	18:50–20:25 (good, 1.58 h)	87.2° 14:05	11.33	52%	118.4°
2045-01-10 Tue	38	—	unknown	18:50–20:20 (good, 1.5 h)	87.2° 14:00	11.32	42%	113.6°
2045-01-11 Wed	36	—	unknown	18:55–20:15 (good, 1.33 h)	87.2° 13:55	11.3	32%	108.0°
2045-01-12 Thu	34	—	unknown	18:55–20:10 (good, 1.25 h)	87.2° 13:50	11.28	23%	101.7°
2045-01-13 Fri	33	—	unknown	18:55–20:10 (good, 1.25 h)	87.2° 13:50	11.26	16%	95.2°
2045-01-14 Sat	32	—	unknown	18:55–20:05 (good, 1.17 h)	87.2° 13:45	11.24	9%	88.6°
2045-01-15 Sun	30	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:40	11.22	5%	82.1°
2045-01-16 Mon	28	—	unknown	19:00–19:55 (good, 0.92 h)	87.2° 13:35	11.19	2%	75.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-12-18&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.