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: 10-25 (100), 10-26 (100), 10-27 (100), 10-28 (100), 10-29 (100) — by astronomy; check the weather when the night is within four days.

2027-10-25astronomy score per night — click a bar for that night2027-11-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2027-10-25 Mon	100	—	unknown	20:00–05:55 (good, 9.92 h)	89.7° 23:50	10.23	16%	129.4°
2027-10-26 Tue	100	—	unknown	20:00–05:55 (good, 9.92 h)	89.7° 23:45	10.27	9%	139.9°
2027-10-27 Wed	100	—	unknown	20:00–05:50 (good, 9.83 h)	89.6° 23:40	10.31	4%	148.0°
2027-10-28 Thu	100	—	unknown	19:55–05:45 (good, 9.83 h)	89.5° 23:35	10.34	1%	151.6°
2027-10-29 Fri	100	—	unknown	19:55–05:40 (good, 9.75 h)	89.6° 23:35	10.38	0%	149.2°
2027-10-30 Sat	100	—	unknown	19:55–04:40 (good, 9.75 h)	89.7° 23:30	10.42	2%	142.3°
2027-10-31 Sun	100	—	unknown	18:55–04:35 (good, 9.67 h)	89.7° 22:25	10.46	6%	133.1°
2027-11-01 Mon	100	—	unknown	18:55–04:30 (good, 9.58 h)	89.6° 22:20	10.49	12%	122.9°
2027-11-02 Tue	100	—	unknown	18:50–04:25 (good, 9.58 h)	89.5° 22:20	10.53	20%	112.4°
2027-11-03 Wed	100	—	unknown	18:50–04:25 (good, 9.58 h)	89.7° 22:15	10.57	28%	101.8°
2027-11-04 Thu	100	—	unknown	18:50–04:20 (good, 9.5 h)	89.7° 22:10	10.6	37%	91.2°
2027-11-05 Fri	100	—	unknown	18:50–04:15 (good, 9.42 h)	89.7° 22:05	10.64	46%	80.8°
2027-11-06 Sat	100	—	unknown	18:45–04:10 (good, 9.42 h)	89.5° 22:00	10.67	56%	70.4°
2027-11-07 Sun	98	—	unknown	18:45–04:05 (good, 9.33 h)	89.6° 22:00	10.7	65%	60.3°
2027-11-08 Mon	90	—	unknown	21:05–04:05 (good, 7.0 h)	89.7° 21:55	10.74	74%	50.5°
2027-11-09 Tue	83	—	unknown	03:00–04:00 (good, 1.0 h)	89.7° 21:50	10.77	82%	41.4°
2027-11-10 Wed	52	—	unknown	18:45–04:30 (marginal, 9.75 h)	89.6° 21:45	10.8	89%	33.7°
2027-11-11 Thu	34	—	unknown	22:55–04:00 (marginal, 5.08 h)	89.5° 21:40	10.83	94%	29.0°
2027-11-12 Fri	29	—	unknown	18:40–20:40 (marginal, 2.0 h)	89.6° 21:40	10.86	98%	29.1°
2027-11-13 Sat	33	—	unknown	18:40–21:35 (marginal, 2.92 h)	89.7° 21:35	10.89	100%	34.3°
2027-11-14 Sun	48	—	unknown	18:40–00:55 (marginal, 6.25 h)	89.7° 21:30	10.92	99%	43.1°
2027-11-15 Mon	65	—	unknown	18:40–19:45 (good, 1.08 h)	89.6° 21:25	10.95	96%	53.8°
2027-11-16 Tue	100	—	unknown	18:40–22:35 (good, 3.92 h)	89.5° 21:25	10.98	90%	65.5°
2027-11-17 Wed	100	—	unknown	18:40–01:15 (good, 6.58 h)	89.6° 21:20	11.01	83%	77.8°
2027-11-18 Thu	100	—	unknown	18:40–02:50 (good, 8.17 h)	89.7° 21:15	11.04	73%	90.3°
2027-11-19 Fri	100	—	unknown	18:35–03:00 (good, 8.42 h)	89.7° 21:10	11.06	63%	102.8°
2027-11-20 Sat	100	—	unknown	18:35–03:05 (good, 8.5 h)	89.5° 21:05	11.09	51%	115.1°
2027-11-21 Sun	100	—	unknown	18:35–03:05 (good, 8.5 h)	89.6° 21:05	11.11	40%	126.8°
2027-11-22 Mon	100	—	unknown	18:35–03:05 (good, 8.5 h)	89.7° 21:00	11.14	29%	137.5°
2027-11-23 Tue	100	—	unknown	18:35–03:05 (good, 8.5 h)	89.7° 20:55	11.16	20%	146.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2027-10-25&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.