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: 11-02 (100), 11-03 (100), 11-04 (100), 11-05 (100), 11-06 (100) — by astronomy; check the weather when the night is within four days.

2031-10-27astronomy score per night — click a bar for that night2031-11-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-10-27 Mon	68	—	unknown	04:35–04:50 (good, 0.25 h)	89.6° 22:40	10.31	93%	36.8°
2031-10-28 Tue	38	—	unknown	23:45–04:55 (marginal, 5.17 h)	89.5° 22:40	10.34	98%	32.0°
2031-10-29 Wed	35	—	unknown	18:55–21:45 (marginal, 2.83 h)	89.6° 22:35	10.38	100%	31.9°
2031-10-30 Thu	43	—	unknown	18:55–23:20 (marginal, 4.42 h)	89.7° 22:30	10.42	100%	36.5°
2031-10-31 Fri	57	—	unknown	18:55–04:10 (marginal, 9.25 h)	89.7° 22:25	10.46	97%	44.0°
2031-11-01 Sat	66	—	unknown	18:55–20:55 (good, 2.0 h)	89.6° 22:20	10.49	93%	53.1°
2031-11-02 Sun	100	—	unknown	18:50–23:20 (good, 4.5 h)	89.5° 22:20	10.53	87%	62.8°
2031-11-03 Mon	100	—	unknown	18:50–01:50 (good, 7.0 h)	89.7° 22:15	10.57	80%	72.9°
2031-11-04 Tue	100	—	unknown	18:50–03:15 (good, 8.42 h)	89.7° 22:10	10.6	72%	83.0°
2031-11-05 Wed	100	—	unknown	18:50–03:50 (good, 9.0 h)	89.7° 22:05	10.64	63%	93.1°
2031-11-06 Thu	100	—	unknown	18:45–03:55 (good, 9.17 h)	89.5° 22:00	10.67	54%	103.2°
2031-11-07 Fri	100	—	unknown	18:45–04:00 (good, 9.25 h)	89.6° 22:00	10.7	44%	113.1°
2031-11-08 Sat	100	—	unknown	18:45–04:00 (good, 9.25 h)	89.7° 21:55	10.74	35%	122.8°
2031-11-09 Sun	100	—	unknown	18:45–03:55 (good, 9.17 h)	89.7° 21:50	10.77	26%	132.1°
2031-11-10 Mon	100	—	unknown	18:45–03:55 (good, 9.17 h)	89.6° 21:45	10.8	17%	140.3°
2031-11-11 Tue	100	—	unknown	18:45–03:50 (good, 9.08 h)	89.5° 21:45	10.83	10%	146.4°
2031-11-12 Wed	100	—	unknown	18:40–03:45 (good, 9.08 h)	89.6° 21:40	10.86	5%	148.7°
2031-11-13 Thu	100	—	unknown	18:40–03:45 (good, 9.08 h)	89.7° 21:35	10.89	1%	146.0°
2031-11-14 Fri	100	—	unknown	18:40–03:40 (good, 9.0 h)	89.7° 21:30	10.92	0%	138.9°
2031-11-15 Sat	100	—	unknown	18:40–03:35 (good, 8.92 h)	89.6° 21:25	10.95	1%	129.2°
2031-11-16 Sun	100	—	unknown	18:40–03:30 (good, 8.83 h)	89.5° 21:25	10.98	6%	117.9°
2031-11-17 Mon	100	—	unknown	18:40–03:30 (good, 8.83 h)	89.7° 21:20	11.01	12%	105.9°
2031-11-18 Tue	100	—	unknown	18:40–03:25 (good, 8.75 h)	89.8° 21:15	11.04	21%	93.5°
2031-11-19 Wed	100	—	unknown	18:35–03:20 (good, 8.75 h)	89.7° 21:10	11.06	31%	81.2°
2031-11-20 Thu	100	—	unknown	18:35–03:15 (good, 8.67 h)	89.5° 21:05	11.09	42%	69.2°
2031-11-21 Fri	97	—	unknown	18:35–03:10 (good, 8.58 h)	89.6° 21:05	11.11	54%	57.8°
2031-11-22 Sat	88	—	unknown	18:35–03:10 (good, 8.58 h)	89.7° 21:00	11.14	64%	47.4°
2031-11-23 Sun	81	—	unknown	02:25–03:05 (good, 0.67 h)	89.7° 20:55	11.16	75%	38.7°
2031-11-24 Mon	49	—	unknown	18:35–03:25 (marginal, 8.83 h)	89.6° 20:50	11.19	83%	32.9°
2031-11-25 Tue	34	—	unknown	18:35–03:05 (marginal, 8.5 h)	89.5° 20:45	11.21	90%	31.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-10-27&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.