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: 10-20 (100), 10-21 (100), 10-22 (100), 10-23 (100), 10-24 (100) — by astronomy; check the weather when the night is within four days.

2046-10-20astronomy score per night — click a bar for that night2046-11-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-10-20 Sat	100	—	unknown	20:05–04:10 (good, 8.08 h)	89.7° 00:10	10.04	70%	69.5°
2046-10-21 Sun	100	—	unknown	20:05–05:40 (good, 9.58 h)	89.8° 00:05	10.08	60%	80.7°
2046-10-22 Mon	100	—	unknown	20:05–05:50 (good, 9.75 h)	89.8° 00:00	10.12	49%	92.4°
2046-10-23 Tue	100	—	unknown	20:05–05:55 (good, 9.83 h)	89.7° 23:55	10.16	38%	104.4°
2046-10-24 Wed	100	—	unknown	20:00–06:00 (good, 10.0 h)	89.5° 23:55	10.2	28%	116.5°
2046-10-25 Thu	100	—	unknown	20:00–05:55 (good, 9.92 h)	89.7° 23:50	10.24	18%	128.4°
2046-10-26 Fri	100	—	unknown	20:00–05:55 (good, 9.92 h)	89.8° 23:45	10.28	10%	139.5°
2046-10-27 Sat	100	—	unknown	20:00–04:50 (good, 9.83 h)	89.8° 23:40	10.32	4%	148.1°
2046-10-28 Sun	100	—	unknown	18:55–04:45 (good, 9.83 h)	89.6° 22:35	10.36	1%	151.6°
2046-10-29 Mon	100	—	unknown	18:55–04:40 (good, 9.75 h)	89.6° 22:35	10.4	0%	148.2°
2046-10-30 Tue	100	—	unknown	18:55–04:40 (good, 9.75 h)	89.8° 22:30	10.43	3%	139.8°
2046-10-31 Wed	100	—	unknown	18:55–04:35 (good, 9.67 h)	89.8° 22:25	10.47	8%	129.0°
2046-11-01 Thu	100	—	unknown	18:50–04:30 (good, 9.67 h)	89.7° 22:20	10.51	16%	117.4°
2046-11-02 Fri	100	—	unknown	18:50–04:25 (good, 9.58 h)	89.5° 22:15	10.54	25%	105.7°
2046-11-03 Sat	100	—	unknown	18:50–04:20 (good, 9.5 h)	89.6° 22:15	10.58	34%	94.2°
2046-11-04 Sun	100	—	unknown	18:50–04:20 (good, 9.5 h)	89.8° 22:10	10.61	44%	83.0°
2046-11-05 Mon	100	—	unknown	18:50–04:15 (good, 9.42 h)	89.8° 22:05	10.65	54%	72.2°
2046-11-06 Tue	99	—	unknown	18:45–04:10 (good, 9.42 h)	89.7° 22:00	10.68	63%	61.8°
2046-11-07 Wed	92	—	unknown	19:00–04:05 (good, 9.08 h)	89.5° 22:00	10.72	72%	52.0°
2046-11-08 Thu	84	—	unknown	00:30–04:05 (good, 3.58 h)	89.7° 21:55	10.75	80%	42.9°
2046-11-09 Fri	64	—	unknown	03:50–04:00 (good, 0.17 h)	89.8° 21:50	10.78	87%	35.2°
2046-11-10 Sat	38	—	unknown	18:45–04:10 (marginal, 9.42 h)	89.8° 21:45	10.81	93%	29.9°
2046-11-11 Sun	30	—	unknown	00:55–03:45 (marginal, 2.83 h)	89.6° 21:40	10.84	97%	28.4°
2046-11-12 Mon	30	—	unknown	18:40–20:55 (marginal, 2.25 h)	89.6° 21:40	10.87	99%	31.3°
2046-11-13 Tue	39	—	unknown	18:40–22:35 (marginal, 3.92 h)	89.8° 21:35	10.91	100%	37.8°
2046-11-14 Wed	55	—	unknown	18:40–02:25 (marginal, 7.75 h)	89.8° 21:30	10.93	98%	46.4°
2046-11-15 Thu	67	—	unknown	18:40–20:20 (good, 1.67 h)	89.7° 21:25	10.96	95%	56.4°
2046-11-16 Fri	100	—	unknown	18:40–23:00 (good, 4.33 h)	89.5° 21:20	10.99	90%	67.1°
2046-11-17 Sat	100	—	unknown	18:40–01:15 (good, 6.58 h)	89.6° 21:20	11.02	83%	78.3°
2046-11-18 Sun	100	—	unknown	18:40–02:45 (good, 8.08 h)	89.8° 21:15	11.05	74%	89.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-10-20&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.