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: 10-28 (100), 10-29 (100), 10-30 (100), 10-31 (100), 11-01 (100) — by astronomy; check the weather when the night is within four days.

2043-10-28astronomy score per night — click a bar for that night2043-11-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-10-28 Wed	100	—	unknown	18:55–04:45 (good, 9.83 h)	89.6° 22:40	10.35	14%	131.7°
2043-10-29 Thu	100	—	unknown	18:55–04:40 (good, 9.75 h)	89.7° 22:35	10.39	8%	140.1°
2043-10-30 Fri	100	—	unknown	18:55–04:40 (good, 9.75 h)	89.8° 22:30	10.42	3%	146.3°
2043-10-31 Sat	100	—	unknown	18:55–04:35 (good, 9.67 h)	89.7° 22:25	10.46	1%	149.2°
2043-11-01 Sun	100	—	unknown	18:50–04:30 (good, 9.67 h)	89.6° 22:20	10.5	0%	147.9°
2043-11-02 Mon	100	—	unknown	18:50–04:25 (good, 9.58 h)	89.6° 22:20	10.53	1%	143.0°
2043-11-03 Tue	100	—	unknown	18:50–04:25 (good, 9.58 h)	89.8° 22:15	10.57	4%	135.7°
2043-11-04 Wed	100	—	unknown	18:50–04:20 (good, 9.5 h)	89.8° 22:10	10.6	8%	127.1°
2043-11-05 Thu	100	—	unknown	18:50–04:15 (good, 9.42 h)	89.7° 22:05	10.64	14%	117.7°
2043-11-06 Fri	100	—	unknown	18:45–04:10 (good, 9.42 h)	89.5° 22:00	10.67	22%	107.9°
2043-11-07 Sat	100	—	unknown	18:45–04:05 (good, 9.33 h)	89.7° 22:00	10.71	30%	97.7°
2043-11-08 Sun	100	—	unknown	18:45–04:05 (good, 9.33 h)	89.8° 21:55	10.74	39%	87.2°
2043-11-09 Mon	100	—	unknown	18:45–04:00 (good, 9.25 h)	89.8° 21:50	10.77	49%	76.6°
2043-11-10 Tue	100	—	unknown	18:45–03:55 (good, 9.17 h)	89.6° 21:45	10.8	59%	65.9°
2043-11-11 Wed	93	—	unknown	18:45–03:50 (good, 9.08 h)	89.5° 21:45	10.84	69%	55.2°
2043-11-12 Thu	84	—	unknown	23:50–03:50 (good, 4.0 h)	89.7° 21:40	10.87	79%	45.1°
2043-11-13 Fri	55	—	unknown	18:40–04:15 (marginal, 9.58 h)	89.8° 21:35	10.9	87%	36.5°
2043-11-14 Sat	35	—	unknown	18:40–03:45 (marginal, 9.08 h)	89.7° 21:30	10.93	94%	31.3°
2043-11-15 Sun	31	—	unknown	18:40–21:00 (marginal, 2.33 h)	89.6° 21:25	10.96	98%	31.9°
2043-11-16 Mon	38	—	unknown	18:40–22:30 (marginal, 3.83 h)	89.6° 21:25	10.98	100%	38.3°
2043-11-17 Tue	57	—	unknown	18:40–02:55 (marginal, 8.25 h)	89.8° 21:20	11.01	98%	48.3°
2043-11-18 Wed	70	—	unknown	18:40–20:55 (good, 2.25 h)	89.8° 21:15	11.04	94%	60.1°
2043-11-19 Thu	100	—	unknown	18:35–00:15 (good, 5.67 h)	89.7° 21:10	11.07	87%	72.5°
2043-11-20 Fri	100	—	unknown	18:35–02:00 (good, 7.42 h)	89.5° 21:05	11.09	78%	84.9°
2043-11-21 Sat	100	—	unknown	18:35–02:50 (good, 8.25 h)	89.7° 21:05	11.12	68%	97.0°
2043-11-22 Sun	100	—	unknown	18:35–02:55 (good, 8.33 h)	89.8° 21:00	11.14	57%	108.7°
2043-11-23 Mon	100	—	unknown	18:35–03:00 (good, 8.42 h)	89.8° 20:55	11.16	46%	119.6°
2043-11-24 Tue	100	—	unknown	18:35–02:55 (good, 8.33 h)	89.6° 20:50	11.19	36%	129.7°
2043-11-25 Wed	100	—	unknown	18:35–02:55 (good, 8.33 h)	89.5° 20:50	11.21	27%	138.5°
2043-11-26 Thu	100	—	unknown	18:35–02:55 (good, 8.33 h)	89.7° 20:45	11.23	19%	145.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-10-28&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.