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: 11-27 (100), 11-28 (100), 11-29 (100), 11-30 (100), 12-01 (100) — by astronomy; check the weather when the night is within four days.

2026-11-21astronomy score per night — click a bar for that night2026-12-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2026-11-21 Sat	41	—	unknown	18:35–23:50 (marginal, 5.25 h)	87.2° 17:20	11.12	90%	63.1°
2026-11-22 Sun	43	—	unknown	18:35–18:40 (good, 0.08 h)	87.3° 17:15	11.14	96%	69.1°
2026-11-23 Mon	49	—	unknown	18:35–20:00 (good, 1.42 h)	87.3° 17:10	11.17	99%	76.4°
2026-11-24 Tue	60	—	unknown	18:35–20:55 (good, 2.33 h)	87.2° 17:05	11.19	100%	84.5°
2026-11-25 Wed	73	—	unknown	18:35–22:00 (good, 3.42 h)	87.2° 17:05	11.21	97%	92.9°
2026-11-26 Thu	86	—	unknown	18:35–22:50 (good, 4.25 h)	87.2° 17:00	11.23	92%	101.2°
2026-11-27 Fri	100	—	unknown	18:35–22:55 (good, 4.33 h)	87.3° 16:55	11.26	84%	108.8°
2026-11-28 Sat	100	—	unknown	18:35–23:00 (good, 4.42 h)	87.3° 16:50	11.28	75%	115.4°
2026-11-29 Sun	100	—	unknown	18:35–23:00 (good, 4.42 h)	87.2° 16:45	11.3	65%	120.3°
2026-11-30 Mon	100	—	unknown	18:35–23:05 (good, 4.5 h)	87.2° 16:45	11.31	54%	123.3°
2026-12-01 Tue	100	—	unknown	18:35–23:00 (good, 4.42 h)	87.3° 16:40	11.33	43%	124.2°
2026-12-02 Wed	100	—	unknown	18:35–22:55 (good, 4.33 h)	87.3° 16:35	11.35	33%	122.9°
2026-12-03 Thu	100	—	unknown	18:35–22:50 (good, 4.25 h)	87.3° 16:30	11.36	23%	119.9°
2026-12-04 Fri	100	—	unknown	18:35–22:45 (good, 4.17 h)	87.2° 16:25	11.38	16%	115.5°
2026-12-05 Sat	100	—	unknown	18:35–22:45 (good, 4.17 h)	87.2° 16:25	11.39	9%	110.0°
2026-12-06 Sun	100	—	unknown	18:35–22:40 (good, 4.08 h)	87.3° 16:20	11.41	4%	103.9°
2026-12-07 Mon	100	—	unknown	18:35–22:35 (good, 4.0 h)	87.3° 16:15	11.42	1%	97.3°
2026-12-08 Tue	100	—	unknown	18:35–22:30 (good, 3.92 h)	87.2° 16:10	11.43	0%	90.6°
2026-12-09 Wed	100	—	unknown	18:35–22:25 (good, 3.83 h)	87.2° 16:05	11.44	1%	83.9°
2026-12-10 Thu	100	—	unknown	18:35–22:25 (good, 3.83 h)	87.2° 16:05	11.45	3%	77.5°
2026-12-11 Fri	98	—	unknown	18:35–22:20 (good, 3.75 h)	87.3° 16:00	11.46	7%	71.4°
2026-12-12 Sat	92	—	unknown	18:35–22:15 (good, 3.67 h)	87.3° 15:55	11.47	13%	66.0°
2026-12-13 Sun	84	—	unknown	18:35–22:10 (good, 3.58 h)	87.2° 15:50	11.48	20%	61.4°
2026-12-14 Mon	74	—	unknown	18:35–22:10 (good, 3.58 h)	87.2° 15:50	11.49	28%	58.0°
2026-12-15 Tue	63	—	unknown	18:35–21:50 (good, 3.25 h)	87.2° 15:45	11.49	37%	56.0°
2026-12-16 Wed	52	—	unknown	18:35–21:35 (good, 3.0 h)	87.3° 15:40	11.5	47%	55.8°
2026-12-17 Thu	43	—	unknown	18:35–20:40 (good, 2.08 h)	87.3° 15:35	11.5	57%	57.5°
2026-12-18 Fri	36	—	unknown	18:35–19:15 (good, 0.67 h)	87.2° 15:30	11.5	67%	61.0°
2026-12-19 Sat	31	—	unknown	18:35–18:40 (good, 0.08 h)	87.2° 15:30	11.51	77%	66.2°
2026-12-20 Sun	30	—	unknown	18:00–22:00 (marginal, 4.0 h)	87.3° 15:25	11.51	86%	72.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2026-11-21&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.