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: 01-09 (100), 01-10 (100), 01-25 (97), 01-26 (97), 01-24 (95) — by astronomy; check the weather when the night is within four days.

2046-01-09astronomy score per night — click a bar for that night2046-02-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-01-09 Tue	100	—	unknown	18:50–00:00 (good, 5.17 h)	89.7° 17:50	11.34	7%	71.0°
2046-01-10 Wed	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.8° 17:45	11.32	12%	60.9°
2046-01-11 Thu	92	—	unknown	18:50–23:50 (good, 5.0 h)	89.7° 17:40	11.3	19%	51.2°
2046-01-12 Fri	87	—	unknown	18:55–23:45 (good, 4.83 h)	89.6° 17:35	11.28	27%	42.3°
2046-01-13 Sat	79	—	unknown	18:55–23:25 (good, 4.5 h)	89.6° 17:35	11.26	36%	34.7°
2046-01-14 Sun	61	—	unknown	18:55–23:10 (good, 4.25 h)	89.8° 17:30	11.24	45%	29.5°
2046-01-15 Mon	45	—	unknown	18:55–00:05 (marginal, 5.17 h)	89.8° 17:25	11.22	55%	28.4°
2046-01-16 Tue	33	—	unknown	18:55–23:50 (marginal, 4.92 h)	89.7° 17:20	11.2	65%	32.1°
2046-01-17 Wed	27	—	unknown	19:00–23:35 (marginal, 4.58 h)	89.5° 17:15	11.18	75%	39.5°
2046-01-18 Thu	26	—	unknown	19:00–23:20 (marginal, 4.33 h)	89.7° 17:15	11.15	83%	49.3°
2046-01-19 Fri	29	—	unknown	19:00–23:15 (marginal, 4.25 h)	89.8° 17:10	11.13	91%	60.5°
2046-01-20 Sat	37	—	unknown	19:00–19:10 (good, 0.17 h)	89.8° 17:05	11.1	96%	72.8°
2046-01-21 Sun	50	—	unknown	19:00–20:50 (good, 1.83 h)	89.6° 17:00	11.08	100%	85.6°
2046-01-22 Mon	64	—	unknown	19:05–22:15 (good, 3.17 h)	89.6° 17:00	11.05	100%	98.8°
2046-01-23 Tue	80	—	unknown	19:05–22:45 (good, 3.67 h)	89.7° 16:55	11.02	97%	111.9°
2046-01-24 Wed	95	—	unknown	19:05–22:45 (good, 3.67 h)	89.8° 16:50	11.0	92%	124.5°
2046-01-25 Thu	97	—	unknown	19:05–22:45 (good, 3.67 h)	89.7° 16:45	10.97	84%	136.1°
2046-01-26 Fri	97	—	unknown	19:10–22:45 (good, 3.58 h)	89.6° 16:40	10.94	74%	145.6°
2046-01-27 Sat	95	—	unknown	19:10–22:45 (good, 3.58 h)	89.6° 16:40	10.91	64%	151.1°
2046-01-28 Sun	93	—	unknown	19:10–22:45 (good, 3.58 h)	89.8° 16:35	10.88	53%	150.9°
2046-01-29 Mon	91	—	unknown	19:10–22:40 (good, 3.5 h)	89.8° 16:30	10.85	42%	145.3°
2046-01-30 Tue	90	—	unknown	19:10–22:35 (good, 3.42 h)	89.7° 16:25	10.82	32%	136.8°
2046-01-31 Wed	86	—	unknown	19:15–22:30 (good, 3.25 h)	89.5° 16:20	10.79	22%	126.9°
2046-02-01 Thu	83	—	unknown	19:15–22:25 (good, 3.17 h)	89.7° 16:20	10.75	15%	116.5°
2046-02-02 Fri	80	—	unknown	19:15–22:25 (good, 3.17 h)	89.8° 16:15	10.72	8%	105.8°
2046-02-03 Sat	79	—	unknown	19:15–22:20 (good, 3.08 h)	89.8° 16:10	10.69	4%	95.1°
2046-02-04 Sun	76	—	unknown	19:20–22:15 (good, 2.92 h)	89.6° 16:05	10.65	1%	84.4°
2046-02-05 Mon	73	—	unknown	19:20–22:10 (good, 2.83 h)	89.5° 16:05	10.62	0%	73.9°
2046-02-06 Tue	71	—	unknown	19:20–22:10 (good, 2.83 h)	89.7° 16:00	10.58	1%	63.7°
2046-02-07 Wed	68	—	unknown	19:20–22:05 (good, 2.75 h)	89.8° 15:55	10.54	4%	53.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-01-09&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.