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: 12-19 (82), 12-20 (82), 12-18 (79), 12-21 (79), 12-22 (77) — by astronomy; check the weather when the night is within four days.

2043-12-17astronomy score per night — click a bar for that night2044-01-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-12-17 Thu	63	—	unknown	18:35–21:35 (good, 3.0 h)	87.2° 15:35	11.5	96%	105.6°
2043-12-18 Fri	79	—	unknown	18:35–21:40 (good, 3.08 h)	87.2° 15:35	11.5	90%	112.0°
2043-12-19 Sat	82	—	unknown	18:35–21:40 (good, 3.08 h)	87.2° 15:30	11.51	82%	117.0°
2043-12-20 Sun	82	—	unknown	18:35–21:45 (good, 3.17 h)	87.2° 15:25	11.51	73%	120.2°
2043-12-21 Mon	79	—	unknown	18:35–21:40 (good, 3.08 h)	87.2° 15:20	11.51	63%	121.5°
2043-12-22 Tue	77	—	unknown	18:35–21:40 (good, 3.08 h)	87.2° 15:15	11.51	53%	121.0°
2043-12-23 Wed	74	—	unknown	18:40–21:35 (good, 2.92 h)	87.2° 15:15	11.51	43%	118.8°
2043-12-24 Thu	72	—	unknown	18:40–21:30 (good, 2.83 h)	87.2° 15:10	11.5	33%	115.3°
2043-12-25 Fri	70	—	unknown	18:40–21:25 (good, 2.75 h)	87.2° 15:05	11.5	25%	110.8°
2043-12-26 Sat	68	—	unknown	18:40–21:20 (good, 2.67 h)	87.2° 15:00	11.5	17%	105.6°
2043-12-27 Sun	67	—	unknown	18:40–21:20 (good, 2.67 h)	87.2° 15:00	11.49	11%	99.8°
2043-12-28 Mon	65	—	unknown	18:40–21:15 (good, 2.58 h)	87.2° 14:55	11.49	6%	93.8°
2043-12-29 Tue	63	—	unknown	18:40–21:10 (good, 2.5 h)	87.2° 14:50	11.48	2%	87.6°
2043-12-30 Wed	60	—	unknown	18:40–21:05 (good, 2.42 h)	87.2° 14:45	11.47	0%	81.4°
2043-12-31 Thu	57	—	unknown	18:45–21:00 (good, 2.25 h)	87.2° 14:40	11.46	0%	75.5°
2044-01-01 Fri	56	—	unknown	18:45–21:00 (good, 2.25 h)	87.2° 14:40	11.45	2%	70.0°
2044-01-02 Sat	54	—	unknown	18:45–20:55 (good, 2.17 h)	87.2° 14:35	11.44	6%	65.3°
2044-01-03 Sun	49	—	unknown	18:45–20:50 (good, 2.08 h)	87.2° 14:30	11.43	11%	61.5°
2044-01-04 Mon	44	—	unknown	18:45–20:40 (good, 1.92 h)	87.2° 14:25	11.42	18%	59.1°
2044-01-05 Tue	38	—	unknown	18:45–20:30 (good, 1.75 h)	87.2° 14:20	11.41	27%	58.3°
2044-01-06 Wed	32	—	unknown	18:45–20:20 (good, 1.58 h)	87.2° 14:20	11.39	37%	59.3°
2044-01-07 Thu	26	—	unknown	18:50–20:05 (good, 1.25 h)	87.2° 14:15	11.38	47%	62.1°
2044-01-08 Fri	21	—	unknown	18:50–19:10 (good, 0.33 h)	87.2° 14:10	11.36	58%	66.5°
2044-01-09 Sat	19	—	unknown	18:50–20:55 (marginal, 2.08 h)	87.2° 14:05	11.35	69%	72.3°
2044-01-10 Sun	17	—	unknown	18:50–20:45 (marginal, 1.92 h)	87.2° 14:05	11.33	80%	79.3°
2044-01-11 Mon	17	—	unknown	18:50–20:45 (marginal, 1.92 h)	87.2° 14:00	11.31	88%	86.9°
2044-01-12 Tue	18	—	unknown	18:55–19:10 (good, 0.25 h)	87.2° 13:55	11.29	95%	94.7°
2044-01-13 Wed	21	—	unknown	18:55–19:40 (good, 0.75 h)	87.2° 13:50	11.27	99%	102.4°
2044-01-14 Thu	23	—	unknown	18:55–19:45 (good, 0.83 h)	87.2° 13:45	11.25	100%	109.3°
2044-01-15 Fri	25	—	unknown	18:55–19:50 (good, 0.92 h)	87.2° 13:45	11.23	98%	115.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-12-17&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.