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: 10-10 (100), 10-11 (100), 10-12 (100), 10-13 (100), 10-22 (100) — by astronomy; check the weather when the night is within four days.

2043-10-10astronomy score per night — click a bar for that night2043-11-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-10-10 Sat	100	—	unknown	20:25–06:00 (good, 9.58 h)	89.7° 00:50	9.59	46%	104.9°
2043-10-11 Sun	100	—	unknown	20:20–06:00 (good, 9.67 h)	89.8° 00:45	9.64	56%	94.5°
2043-10-12 Mon	100	—	unknown	20:20–06:00 (good, 9.67 h)	89.8° 00:40	9.68	66%	83.8°
2043-10-13 Tue	100	—	unknown	20:20–06:00 (good, 9.67 h)	89.6° 00:35	9.73	75%	72.8°
2043-10-14 Wed	98	—	unknown	21:15–06:05 (good, 8.83 h)	89.6° 00:35	9.77	84%	61.8°
2043-10-15 Thu	88	—	unknown	02:45–06:05 (good, 3.33 h)	89.7° 00:30	9.82	91%	51.0°
2043-10-16 Fri	80	—	unknown	06:00–06:05 (good, 0.08 h)	89.8° 00:25	9.86	96%	41.1°
2043-10-17 Sat	39	—	unknown	01:10–06:05 (marginal, 4.92 h)	89.7° 00:20	9.9	100%	33.6°
2043-10-18 Sun	36	—	unknown	20:10–23:15 (marginal, 3.08 h)	89.6° 00:15	9.94	100%	30.8°
2043-10-19 Mon	45	—	unknown	20:10–00:50 (marginal, 4.67 h)	89.6° 00:15	9.99	97%	34.2°
2043-10-20 Tue	58	—	unknown	20:10–05:55 (marginal, 9.75 h)	89.8° 00:10	10.03	91%	42.3°
2043-10-21 Wed	92	—	unknown	20:05–23:30 (good, 3.42 h)	89.8° 00:05	10.07	84%	53.0°
2043-10-22 Thu	100	—	unknown	20:05–03:10 (good, 7.08 h)	89.7° 00:00	10.11	74%	64.6°
2043-10-23 Fri	100	—	unknown	20:05–05:00 (good, 8.92 h)	89.5° 00:00	10.15	63%	76.6°
2043-10-24 Sat	100	—	unknown	20:00–04:40 (good, 9.67 h)	89.7° 23:55	10.19	52%	88.5°
2043-10-25 Sun	100	—	unknown	19:00–04:45 (good, 9.75 h)	89.8° 22:50	10.23	41%	100.2°
2043-10-26 Mon	100	—	unknown	19:00–04:50 (good, 9.83 h)	89.8° 22:45	10.27	31%	111.4°
2043-10-27 Tue	100	—	unknown	19:00–04:50 (good, 9.83 h)	89.6° 22:40	10.31	22%	122.0°
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°

Download: CSV · JSON

💡 API

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