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: 10-03 (100), 10-04 (100), 10-05 (100), 10-06 (100), 10-07 (100) — by astronomy; check the weather when the night is within four days.

2034-09-26astronomy score per night — click a bar for that night2034-10-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-09-26 Tue	59	—	unknown	20:45–05:45 (marginal, 9.0 h)	89.5° 01:40	8.94	98%	49.8°
2034-09-27 Wed	49	—	unknown	20:45–05:45 (marginal, 9.0 h)	89.6° 01:40	8.99	100%	41.8°
2034-09-28 Thu	43	—	unknown	20:45–05:45 (marginal, 9.0 h)	89.8° 01:35	9.04	99%	36.9°
2034-09-29 Fri	52	—	unknown	20:40–05:45 (marginal, 9.08 h)	89.7° 01:30	9.09	95%	36.7°
2034-09-30 Sat	86	—	unknown	20:40–20:55 (good, 0.25 h)	89.6° 01:25	9.13	89%	41.4°
2034-10-01 Sun	92	—	unknown	20:40–00:30 (good, 3.83 h)	89.5° 01:25	9.18	80%	49.5°
2034-10-02 Mon	99	—	unknown	20:35–04:20 (good, 7.75 h)	89.7° 01:20	9.23	70%	59.4°
2034-10-03 Tue	100	—	unknown	20:35–05:50 (good, 9.25 h)	89.8° 01:15	9.28	59%	70.2°
2034-10-04 Wed	100	—	unknown	20:35–05:50 (good, 9.25 h)	89.7° 01:10	9.33	48%	81.2°
2034-10-05 Thu	100	—	unknown	20:30–05:55 (good, 9.42 h)	89.5° 01:05	9.37	37%	92.2°
2034-10-06 Fri	100	—	unknown	20:30–05:55 (good, 9.42 h)	89.6° 01:05	9.42	27%	103.0°
2034-10-07 Sat	100	—	unknown	20:30–05:55 (good, 9.42 h)	89.7° 01:00	9.47	18%	113.2°
2034-10-08 Sun	100	—	unknown	20:25–05:55 (good, 9.5 h)	89.8° 00:55	9.51	11%	122.8°
2034-10-09 Mon	100	—	unknown	20:25–06:00 (good, 9.58 h)	89.7° 00:50	9.56	6%	131.3°
2034-10-10 Tue	100	—	unknown	20:25–06:00 (good, 9.58 h)	89.5° 00:45	9.6	2%	138.1°
2034-10-11 Wed	100	—	unknown	20:20–06:00 (good, 9.67 h)	89.6° 00:45	9.65	0%	142.6°
2034-10-12 Thu	100	—	unknown	20:20–06:00 (good, 9.67 h)	89.8° 00:40	9.69	0%	143.8°
2034-10-13 Fri	100	—	unknown	20:20–06:00 (good, 9.67 h)	89.7° 00:35	9.74	2%	141.7°
2034-10-14 Sat	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.6° 00:30	9.78	6%	136.7°
2034-10-15 Sun	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.5° 00:30	9.82	12%	129.9°
2034-10-16 Mon	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.7° 00:25	9.87	18%	121.8°
2034-10-17 Tue	100	—	unknown	20:10–06:05 (good, 9.92 h)	89.8° 00:20	9.91	26%	113.0°
2034-10-18 Wed	100	—	unknown	20:10–06:05 (good, 9.92 h)	89.7° 00:15	9.95	35%	103.7°
2034-10-19 Thu	100	—	unknown	20:10–06:10 (good, 10.0 h)	89.6° 00:10	9.99	44%	94.0°
2034-10-20 Fri	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.6° 00:10	10.04	54%	84.0°
2034-10-21 Sat	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.7° 00:05	10.08	64%	73.9°
2034-10-22 Sun	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.8° 00:00	10.12	74%	63.7°
2034-10-23 Mon	92	—	unknown	00:20–06:05 (good, 5.75 h)	89.7° 23:55	10.16	83%	53.9°
2034-10-24 Tue	83	—	unknown	04:55–06:00 (good, 1.08 h)	89.5° 23:50	10.2	90%	45.2°
2034-10-25 Wed	54	—	unknown	20:00–06:15 (marginal, 10.25 h)	89.6° 23:50	10.24	96%	38.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-09-26&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.