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 Andromeda Galaxy: 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.

2026-11-26astronomy score per night — click a bar for that night2026-12-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2026-11-26 Thu	76	—	unknown	18:35–23:00 (good, 4.42 h)	89.5° 20:40	11.23	92%	70.6°
2026-11-27 Fri	100	—	unknown	18:35–01:05 (good, 6.5 h)	89.6° 20:40	11.26	84%	83.6°
2026-11-28 Sat	100	—	unknown	18:35–02:15 (good, 7.67 h)	89.7° 20:35	11.28	75%	96.4°
2026-11-29 Sun	100	—	unknown	18:35–02:25 (good, 7.83 h)	89.7° 20:30	11.3	65%	108.8°
2026-11-30 Mon	100	—	unknown	18:35–02:30 (good, 7.92 h)	89.6° 20:25	11.31	54%	120.5°
2026-12-01 Tue	100	—	unknown	18:35–02:25 (good, 7.83 h)	89.5° 20:25	11.33	43%	131.4°
2026-12-02 Wed	100	—	unknown	18:35–02:25 (good, 7.83 h)	89.6° 20:20	11.35	33%	140.8°
2026-12-03 Thu	100	—	unknown	18:35–02:25 (good, 7.83 h)	89.7° 20:15	11.36	23%	147.8°
2026-12-04 Fri	100	—	unknown	18:35–02:20 (good, 7.75 h)	89.7° 20:10	11.38	16%	151.1°
2026-12-05 Sat	100	—	unknown	18:35–02:15 (good, 7.67 h)	89.5° 20:05	11.39	9%	149.7°
2026-12-06 Sun	100	—	unknown	18:35–02:10 (good, 7.58 h)	89.6° 20:05	11.41	4%	144.2°
2026-12-07 Mon	100	—	unknown	18:35–02:10 (good, 7.58 h)	89.7° 20:00	11.42	1%	136.3°
2026-12-08 Tue	100	—	unknown	18:35–02:05 (good, 7.5 h)	89.7° 19:55	11.43	0%	127.2°
2026-12-09 Wed	100	—	unknown	18:35–02:00 (good, 7.42 h)	89.6° 19:50	11.44	1%	117.4°
2026-12-10 Thu	100	—	unknown	18:35–01:55 (good, 7.33 h)	89.5° 19:45	11.45	3%	107.3°
2026-12-11 Fri	100	—	unknown	18:35–01:50 (good, 7.25 h)	89.6° 19:45	11.46	7%	97.0°
2026-12-12 Sat	100	—	unknown	18:35–01:50 (good, 7.25 h)	89.7° 19:40	11.47	13%	86.6°
2026-12-13 Sun	100	—	unknown	18:35–01:45 (good, 7.17 h)	89.7° 19:35	11.48	20%	76.2°
2026-12-14 Mon	100	—	unknown	18:35–01:40 (good, 7.08 h)	89.6° 19:30	11.49	28%	65.9°
2026-12-15 Tue	95	—	unknown	18:35–01:35 (good, 7.0 h)	89.5° 19:30	11.49	37%	55.7°
2026-12-16 Wed	87	—	unknown	18:35–01:30 (good, 6.92 h)	89.6° 19:25	11.5	47%	46.0°
2026-12-17 Thu	76	—	unknown	18:35–01:30 (good, 6.92 h)	89.7° 19:20	11.5	57%	37.2°
2026-12-18 Fri	55	—	unknown	18:35–01:55 (marginal, 7.33 h)	89.7° 19:15	11.5	67%	30.8°
2026-12-19 Sat	36	—	unknown	18:35–01:35 (marginal, 7.0 h)	89.5° 19:10	11.51	77%	28.7°
2026-12-20 Sun	26	—	unknown	18:35–01:10 (marginal, 6.58 h)	89.5° 19:10	11.51	86%	32.6°
2026-12-21 Mon	27	—	unknown	18:35–00:50 (marginal, 6.25 h)	89.7° 19:05	11.51	93%	41.1°
2026-12-22 Tue	36	—	unknown	18:35–00:45 (marginal, 6.17 h)	89.7° 19:00	11.51	98%	52.3°
2026-12-23 Wed	52	—	unknown	18:40–18:55 (good, 0.25 h)	89.6° 18:55	11.51	100%	64.8°
2026-12-24 Thu	72	—	unknown	18:40–21:50 (good, 3.17 h)	89.5° 18:50	11.5	99%	78.0°
2026-12-25 Fri	100	—	unknown	18:40–23:30 (good, 4.83 h)	89.6° 18:50	11.5	95%	91.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2026-11-26&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.