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.

2035-10-13astronomy score per night — click a bar for that night2035-11-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-10-13 Sat	93	—	unknown	01:25–06:00 (good, 4.58 h)	89.6° 00:35	9.73	89%	55.6°
2035-10-14 Sun	85	—	unknown	05:20–06:05 (good, 0.75 h)	89.5° 00:35	9.77	94%	47.4°
2035-10-15 Mon	50	—	unknown	20:15–06:05 (marginal, 9.83 h)	89.7° 00:30	9.81	98%	41.0°
2035-10-16 Tue	46	—	unknown	20:15–06:05 (marginal, 9.83 h)	89.8° 00:25	9.86	100%	37.6°
2035-10-17 Wed	51	—	unknown	20:10–06:05 (marginal, 9.92 h)	89.7° 00:20	9.9	99%	38.4°
2035-10-18 Thu	58	—	unknown	20:10–06:05 (marginal, 9.92 h)	89.6° 00:15	9.94	96%	43.3°
2035-10-19 Fri	93	—	unknown	20:10–22:45 (good, 2.58 h)	89.6° 00:15	9.98	90%	51.2°
2035-10-20 Sat	100	—	unknown	20:10–01:35 (good, 5.42 h)	89.7° 00:10	10.03	82%	61.0°
2035-10-21 Sun	100	—	unknown	20:05–04:10 (good, 8.08 h)	89.8° 00:05	10.07	72%	71.7°
2035-10-22 Mon	100	—	unknown	20:05–05:40 (good, 9.58 h)	89.7° 00:00	10.11	61%	82.9°
2035-10-23 Tue	100	—	unknown	20:05–05:50 (good, 9.75 h)	89.5° 23:55	10.15	50%	94.1°
2035-10-24 Wed	100	—	unknown	20:00–05:55 (good, 9.92 h)	89.6° 23:55	10.19	38%	105.1°
2035-10-25 Thu	100	—	unknown	20:00–05:55 (good, 9.92 h)	89.7° 23:50	10.23	28%	115.6°
2035-10-26 Fri	100	—	unknown	20:00–05:50 (good, 9.83 h)	89.8° 23:45	10.27	19%	125.3°
2035-10-27 Sat	100	—	unknown	20:00–04:50 (good, 9.83 h)	89.6° 23:40	10.31	11%	133.5°
2035-10-28 Sun	100	—	unknown	18:55–04:45 (good, 9.83 h)	89.5° 22:40	10.35	5%	139.6°
2035-10-29 Mon	100	—	unknown	18:55–04:45 (good, 9.83 h)	89.7° 22:35	10.38	2%	142.5°
2035-10-30 Tue	100	—	unknown	18:55–04:40 (good, 9.75 h)	89.8° 22:30	10.42	0%	141.6°
2035-10-31 Wed	100	—	unknown	18:55–04:35 (good, 9.67 h)	89.7° 22:25	10.46	1%	137.5°
2035-11-01 Thu	100	—	unknown	18:50–04:30 (good, 9.67 h)	89.6° 22:20	10.49	3%	131.0°
2035-11-02 Fri	100	—	unknown	18:50–04:25 (good, 9.58 h)	89.6° 22:20	10.53	8%	123.2°
2035-11-03 Sat	100	—	unknown	18:50–04:25 (good, 9.58 h)	89.7° 22:15	10.57	14%	114.5°
2035-11-04 Sun	100	—	unknown	18:50–04:20 (good, 9.5 h)	89.8° 22:10	10.6	21%	105.5°
2035-11-05 Mon	100	—	unknown	18:50–04:15 (good, 9.42 h)	89.7° 22:05	10.64	29%	96.2°
2035-11-06 Tue	100	—	unknown	18:45–04:10 (good, 9.42 h)	89.5° 22:00	10.67	38%	86.8°
2035-11-07 Wed	100	—	unknown	18:45–04:05 (good, 9.33 h)	89.6° 22:00	10.7	47%	77.4°
2035-11-08 Thu	100	—	unknown	18:45–04:05 (good, 9.33 h)	89.7° 21:55	10.74	56%	68.1°
2035-11-09 Fri	97	—	unknown	18:45–04:00 (good, 9.25 h)	89.8° 21:50	10.77	66%	59.1°
2035-11-10 Sat	88	—	unknown	21:25–03:55 (good, 6.5 h)	89.6° 21:45	10.8	75%	50.7°
2035-11-11 Sun	81	—	unknown	03:05–03:50 (good, 0.75 h)	89.5° 21:45	10.83	84%	43.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-10-13&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.