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: 11-18 (100), 11-19 (100), 11-20 (100), 11-21 (100), 11-22 (100) — by astronomy; check the weather when the night is within four days.

2030-11-18astronomy score per night — click a bar for that night2030-12-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-11-18 Mon	100	—	unknown	18:40–23:50 (good, 5.17 h)	87.2° 17:30	11.04	44%	127.6°
2030-11-19 Tue	100	—	unknown	18:35–23:45 (good, 5.17 h)	87.2° 17:25	11.07	34%	127.5°
2030-11-20 Wed	100	—	unknown	18:35–23:40 (good, 5.08 h)	87.2° 17:20	11.1	24%	125.1°
2030-11-21 Thu	100	—	unknown	18:35–23:40 (good, 5.08 h)	87.2° 17:20	11.12	16%	120.5°
2030-11-22 Fri	100	—	unknown	18:35–23:35 (good, 5.0 h)	87.2° 17:15	11.14	8%	114.0°
2030-11-23 Sat	100	—	unknown	18:35–23:30 (good, 4.92 h)	87.2° 17:10	11.17	3%	106.0°
2030-11-24 Sun	100	—	unknown	18:35–23:25 (good, 4.83 h)	87.2° 17:05	11.19	0%	97.1°
2030-11-25 Mon	100	—	unknown	18:35–23:25 (good, 4.83 h)	87.2° 17:05	11.21	1%	87.8°
2030-11-26 Tue	100	—	unknown	18:35–23:20 (good, 4.75 h)	87.2° 17:00	11.24	4%	78.7°
2030-11-27 Wed	100	—	unknown	18:35–23:15 (good, 4.67 h)	87.2° 16:55	11.26	10%	70.1°
2030-11-28 Thu	94	—	unknown	18:35–23:10 (good, 4.58 h)	87.2° 16:50	11.28	18%	62.7°
2030-11-29 Fri	88	—	unknown	18:35–23:05 (good, 4.5 h)	87.2° 16:45	11.3	28%	57.0°
2030-11-30 Sat	81	—	unknown	18:35–23:05 (good, 4.5 h)	87.2° 16:45	11.31	39%	53.4°
2030-12-01 Sun	65	—	unknown	18:35–22:35 (good, 4.0 h)	87.2° 16:40	11.33	50%	52.2°
2030-12-02 Mon	52	—	unknown	18:35–21:20 (good, 2.75 h)	87.2° 16:35	11.35	60%	53.4°
2030-12-03 Tue	44	—	unknown	18:35–19:40 (good, 1.08 h)	87.2° 16:30	11.36	70%	56.6°
2030-12-04 Wed	39	—	unknown	18:35–23:05 (marginal, 4.5 h)	87.2° 16:25	11.38	78%	61.3°
2030-12-05 Thu	38	—	unknown	18:00–23:00 (marginal, 5.0 h)	87.2° 16:25	11.39	86%	67.1°
2030-12-06 Fri	39	—	unknown	18:35–19:15 (good, 0.67 h)	87.2° 16:20	11.41	92%	73.7°
2030-12-07 Sat	44	—	unknown	18:35–19:45 (good, 1.17 h)	87.2° 16:15	11.42	96%	80.7°
2030-12-08 Sun	50	—	unknown	18:35–20:25 (good, 1.83 h)	87.2° 16:10	11.43	99%	87.9°
2030-12-09 Mon	58	—	unknown	18:35–21:10 (good, 2.58 h)	87.2° 16:05	11.44	100%	95.2°
2030-12-10 Tue	66	—	unknown	18:35–21:50 (good, 3.25 h)	87.2° 16:05	11.45	99%	102.3°
2030-12-11 Wed	74	—	unknown	18:35–21:55 (good, 3.33 h)	87.2° 16:00	11.46	96%	109.1°
2030-12-12 Thu	89	—	unknown	18:35–22:00 (good, 3.42 h)	87.2° 15:55	11.47	92%	115.2°
2030-12-13 Fri	91	—	unknown	18:35–22:00 (good, 3.42 h)	87.2° 15:50	11.48	86%	120.6°
2030-12-14 Sat	92	—	unknown	18:35–22:00 (good, 3.42 h)	87.2° 15:50	11.49	79%	124.7°
2030-12-15 Sun	91	—	unknown	18:35–22:05 (good, 3.5 h)	87.2° 15:45	11.49	70%	127.2°
2030-12-16 Mon	89	—	unknown	18:35–22:00 (good, 3.42 h)	87.2° 15:40	11.5	61%	127.7°
2030-12-17 Tue	87	—	unknown	18:35–21:55 (good, 3.33 h)	87.2° 15:35	11.5	51%	126.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-11-18&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.