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: 10-29 (100), 10-30 (100), 10-31 (100), 11-01 (100), 11-02 (100) — by astronomy; check the weather when the night is within four days.

2041-10-29astronomy score per night — click a bar for that night2041-11-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-10-29 Tue	100	—	unknown	18:55–04:40 (good, 9.75 h)	89.6° 22:30	10.4	23%	112.2°
2041-10-30 Wed	100	—	unknown	18:55–04:35 (good, 9.67 h)	89.6° 22:30	10.44	33%	101.3°
2041-10-31 Thu	100	—	unknown	18:55–04:35 (good, 9.67 h)	89.7° 22:25	10.48	44%	90.0°
2041-11-01 Fri	100	—	unknown	18:50–04:30 (good, 9.67 h)	89.8° 22:20	10.51	55%	78.5°
2041-11-02 Sat	100	—	unknown	18:50–04:25 (good, 9.58 h)	89.7° 22:15	10.55	66%	67.0°
2041-11-03 Sun	92	—	unknown	18:50–04:20 (good, 9.5 h)	89.5° 22:10	10.59	76%	56.0°
2041-11-04 Mon	83	—	unknown	03:15–04:15 (good, 1.0 h)	89.6° 22:10	10.62	86%	45.9°
2041-11-05 Tue	48	—	unknown	18:50–04:45 (marginal, 9.92 h)	89.8° 22:05	10.66	93%	38.1°
2041-11-06 Wed	39	—	unknown	18:45–04:10 (marginal, 9.42 h)	89.8° 22:00	10.69	98%	34.1°
2041-11-07 Thu	38	—	unknown	18:45–22:20 (marginal, 3.58 h)	89.7° 21:55	10.72	100%	35.5°
2041-11-08 Fri	48	—	unknown	18:45–01:00 (marginal, 6.25 h)	89.5° 21:55	10.76	99%	41.3°
2041-11-09 Sat	62	—	unknown	18:45–19:30 (good, 0.75 h)	89.7° 21:50	10.79	96%	49.9°
2041-11-10 Sun	72	—	unknown	18:45–21:40 (good, 2.92 h)	89.8° 21:45	10.82	91%	59.8°
2041-11-11 Mon	100	—	unknown	18:40–00:45 (good, 6.08 h)	89.8° 21:40	10.85	84%	70.2°
2041-11-12 Tue	100	—	unknown	18:40–02:15 (good, 7.58 h)	89.6° 21:35	10.88	76%	80.6°
2041-11-13 Wed	100	—	unknown	18:40–03:15 (good, 8.58 h)	89.6° 21:35	10.91	67%	90.9°
2041-11-14 Thu	100	—	unknown	18:40–03:20 (good, 8.67 h)	89.7° 21:30	10.94	57%	101.0°
2041-11-15 Fri	100	—	unknown	18:40–03:25 (good, 8.75 h)	89.8° 21:25	10.97	48%	110.7°
2041-11-16 Sat	100	—	unknown	18:40–03:25 (good, 8.75 h)	89.7° 21:20	11.0	38%	120.0°
2041-11-17 Sun	100	—	unknown	18:40–03:25 (good, 8.75 h)	89.5° 21:15	11.03	29%	128.7°
2041-11-18 Mon	100	—	unknown	18:35–03:20 (good, 8.75 h)	89.6° 21:15	11.05	21%	136.4°
2041-11-19 Tue	100	—	unknown	18:35–03:20 (good, 8.75 h)	89.8° 21:10	11.08	14%	142.4°
2041-11-20 Wed	100	—	unknown	18:35–03:15 (good, 8.67 h)	89.8° 21:05	11.1	8%	145.7°
2041-11-21 Thu	100	—	unknown	18:35–03:10 (good, 8.58 h)	89.7° 21:00	11.13	3%	145.3°
2041-11-22 Fri	100	—	unknown	18:35–03:05 (good, 8.5 h)	89.5° 21:00	11.15	1%	141.2°
2041-11-23 Sat	100	—	unknown	18:35–03:05 (good, 8.5 h)	89.7° 20:55	11.18	0%	134.1°
2041-11-24 Sun	100	—	unknown	18:35–03:00 (good, 8.42 h)	89.8° 20:50	11.2	2%	125.0°
2041-11-25 Mon	100	—	unknown	18:35–02:55 (good, 8.33 h)	89.8° 20:45	11.22	6%	114.8°
2041-11-26 Tue	100	—	unknown	18:35–02:50 (good, 8.25 h)	89.6° 20:40	11.24	12%	103.8°
2041-11-27 Wed	100	—	unknown	18:35–02:45 (good, 8.17 h)	89.6° 20:40	11.26	20%	92.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-10-29&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.