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: 12-29 (43), 01-11 (37), 12-30 (36), 01-10 (36), 01-12 (35) — by astronomy; check the weather when the night is within four days.

2030-12-29astronomy score per night — click a bar for that night2031-01-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-12-29 Sun	43	—	unknown	18:40–20:50 (good, 2.17 h)	87.2° 14:50	11.48	33%	52.9°
2030-12-30 Mon	36	—	unknown	18:40–20:40 (good, 2.0 h)	87.2° 14:45	11.47	44%	55.6°
2030-12-31 Tue	29	—	unknown	18:45–20:00 (good, 1.25 h)	87.2° 14:40	11.46	54%	60.0°
2031-01-01 Wed	25	—	unknown	18:45–19:00 (good, 0.25 h)	87.2° 14:35	11.45	64%	65.7°
2031-01-02 Thu	23	—	unknown	18:45–21:20 (marginal, 2.58 h)	87.2° 14:35	11.44	72%	72.1°
2031-01-03 Fri	23	—	unknown	18:45–21:15 (marginal, 2.5 h)	87.2° 14:30	11.43	81%	79.0°
2031-01-04 Sat	23	—	unknown	18:45–19:00 (good, 0.25 h)	87.2° 14:25	11.42	88%	86.2°
2031-01-05 Sun	25	—	unknown	18:45–19:30 (good, 0.75 h)	87.2° 14:20	11.4	93%	93.4°
2031-01-06 Mon	26	—	unknown	18:50–20:00 (good, 1.17 h)	87.2° 14:15	11.39	97%	100.6°
2031-01-07 Tue	29	—	unknown	18:50–20:10 (good, 1.33 h)	87.2° 14:15	11.38	99%	107.4°
2031-01-08 Wed	32	—	unknown	18:50–20:10 (good, 1.33 h)	87.2° 14:10	11.36	100%	113.8°
2031-01-09 Thu	34	—	unknown	18:50–20:15 (good, 1.42 h)	87.2° 14:05	11.34	99%	119.3°
2031-01-10 Fri	36	—	unknown	18:50–20:10 (good, 1.33 h)	87.2° 14:00	11.33	96%	123.7°
2031-01-11 Sat	37	—	unknown	18:50–20:15 (good, 1.42 h)	87.2° 14:00	11.31	91%	126.6°
2031-01-12 Sun	35	—	unknown	18:55–20:15 (good, 1.33 h)	87.2° 13:55	11.29	84%	127.6°
2031-01-13 Mon	34	—	unknown	18:55–20:10 (good, 1.25 h)	87.2° 13:50	11.27	76%	126.5°
2031-01-14 Tue	32	—	unknown	18:55–20:05 (good, 1.17 h)	87.2° 13:45	11.25	67%	123.4°
2031-01-15 Wed	30	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:40	11.23	56%	118.3°
2031-01-16 Thu	29	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:40	11.21	46%	111.8°
2031-01-17 Fri	27	—	unknown	19:00–19:55 (good, 0.92 h)	87.2° 13:35	11.19	35%	104.1°
2031-01-18 Sat	26	—	unknown	19:00–19:50 (good, 0.83 h)	87.2° 13:30	11.16	24%	95.7°
2031-01-19 Sun	25	—	unknown	19:00–19:45 (good, 0.75 h)	87.2° 13:25	11.14	15%	86.7°
2031-01-20 Mon	23	—	unknown	19:00–19:40 (good, 0.67 h)	87.2° 13:20	11.11	7%	77.8°
2031-01-21 Tue	23	—	unknown	19:00–19:40 (good, 0.67 h)	87.2° 13:20	11.09	2%	69.4°
2031-01-22 Wed	20	—	unknown	19:05–19:35 (good, 0.5 h)	87.2° 13:15	11.06	0%	62.0°
2031-01-23 Thu	19	—	unknown	19:05–19:30 (good, 0.42 h)	87.2° 13:10	11.03	1%	56.4°
2031-01-24 Fri	17	—	unknown	19:05–19:25 (good, 0.33 h)	87.2° 13:05	11.01	4%	53.1°
2031-01-25 Sat	15	—	unknown	19:05–19:20 (good, 0.25 h)	87.2° 13:05	10.98	10%	52.5°
2031-01-26 Sun	13	—	unknown	19:05–19:10 (good, 0.08 h)	87.2° 13:00	10.95	18%	54.5°
2031-01-27 Mon	10	—	unknown	19:10–19:50 (marginal, 0.67 h)	87.2° 12:55	10.92	27%	58.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-12-29&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.