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: 10-12 (100), 10-13 (100), 10-14 (100), 10-15 (100), 10-16 (100) — by astronomy; check the weather when the night is within four days.

2028-10-12astronomy score per night — click a bar for that night2028-11-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-10-12 Thu	100	—	unknown	20:20–06:00 (good, 9.67 h)	89.5° 00:35	9.71	34%	99.6°
2028-10-13 Fri	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.6° 00:35	9.76	24%	112.0°
2028-10-14 Sat	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.7° 00:30	9.8	15%	124.2°
2028-10-15 Sun	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.7° 00:25	9.84	7%	135.8°
2028-10-16 Mon	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.6° 00:20	9.89	2%	145.6°
2028-10-17 Tue	100	—	unknown	20:10–06:05 (good, 9.92 h)	89.5° 00:20	9.93	0%	151.2°
2028-10-18 Wed	100	—	unknown	20:10–06:10 (good, 10.0 h)	89.7° 00:15	9.97	1%	150.1°
2028-10-19 Thu	100	—	unknown	20:10–06:10 (good, 10.0 h)	89.7° 00:10	10.01	5%	143.2°
2028-10-20 Fri	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.7° 00:05	10.06	11%	133.3°
2028-10-21 Sat	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.5° 00:00	10.1	19%	122.2°
2028-10-22 Sun	100	—	unknown	20:05–06:05 (good, 10.0 h)	89.6° 00:00	10.14	28%	110.9°
2028-10-23 Mon	100	—	unknown	20:05–06:05 (good, 10.0 h)	89.7° 23:55	10.18	37%	99.7°
2028-10-24 Tue	100	—	unknown	20:00–06:00 (good, 10.0 h)	89.7° 23:50	10.22	47%	88.6°
2028-10-25 Wed	100	—	unknown	20:00–05:55 (good, 9.92 h)	89.6° 23:45	10.26	57%	77.9°
2028-10-26 Thu	100	—	unknown	20:00–05:50 (good, 9.83 h)	89.5° 23:40	10.3	66%	67.5°
2028-10-27 Fri	96	—	unknown	20:20–05:45 (good, 9.42 h)	89.6° 23:40	10.33	75%	57.4°
2028-10-28 Sat	88	—	unknown	01:20–04:45 (good, 4.42 h)	89.7° 23:35	10.37	82%	48.0°
2028-10-29 Sun	81	—	unknown	03:55–04:40 (good, 0.75 h)	89.7° 22:30	10.41	89%	39.5°
2028-10-30 Mon	46	—	unknown	18:55–05:10 (marginal, 10.25 h)	89.6° 22:25	10.45	94%	32.6°
2028-10-31 Tue	32	—	unknown	00:50–04:35 (marginal, 3.75 h)	89.5° 22:25	10.48	98%	28.8°
2028-11-01 Wed	31	—	unknown	18:50–21:05 (marginal, 2.25 h)	89.7° 22:20	10.52	100%	29.3°
2028-11-02 Thu	37	—	unknown	18:50–22:15 (marginal, 3.42 h)	89.7° 22:15	10.56	100%	34.1°
2028-11-03 Fri	53	—	unknown	18:50–01:50 (marginal, 7.0 h)	89.7° 22:10	10.59	98%	41.9°
2028-11-04 Sat	64	—	unknown	18:50–20:15 (good, 1.42 h)	89.5° 22:05	10.63	94%	51.4°
2028-11-05 Sun	99	—	unknown	18:50–22:50 (good, 4.0 h)	89.6° 22:05	10.66	88%	61.9°
2028-11-06 Mon	100	—	unknown	18:45–01:35 (good, 6.83 h)	89.7° 22:00	10.69	80%	73.1°
2028-11-07 Tue	100	—	unknown	18:45–03:10 (good, 8.42 h)	89.7° 21:55	10.73	71%	84.7°
2028-11-08 Wed	100	—	unknown	18:45–03:40 (good, 8.92 h)	89.6° 21:50	10.76	61%	96.6°
2028-11-09 Thu	100	—	unknown	18:45–03:45 (good, 9.0 h)	89.5° 21:45	10.79	50%	108.6°
2028-11-10 Fri	100	—	unknown	18:45–03:45 (good, 9.0 h)	89.6° 21:45	10.82	38%	120.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-10-12&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.