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: 09-17 (100), 09-18 (100), 09-19 (100), 09-20 (100), 09-21 (100) — by astronomy; check the weather when the night is within four days.

2034-09-17astronomy score per night — click a bar for that night2034-10-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-09-17 Sun	100	—	unknown	21:05–05:35 (good, 8.5 h)	89.5° 02:20	8.48	24%	134.8°
2034-09-18 Mon	100	—	unknown	21:00–05:35 (good, 8.58 h)	89.7° 02:15	8.53	33%	127.5°
2034-09-19 Tue	100	—	unknown	21:00–05:35 (good, 8.58 h)	89.8° 02:10	8.58	42%	119.1°
2034-09-20 Wed	100	—	unknown	21:00–05:35 (good, 8.58 h)	89.7° 02:05	8.64	51%	110.0°
2034-09-21 Thu	100	—	unknown	20:55–05:35 (good, 8.67 h)	89.5° 02:00	8.69	61%	100.4°
2034-09-22 Fri	100	—	unknown	20:55–05:40 (good, 8.75 h)	89.6° 02:00	8.74	71%	90.4°
2034-09-23 Sat	100	—	unknown	20:50–05:40 (good, 8.83 h)	89.7° 01:55	8.79	79%	80.1°
2034-09-24 Sun	100	—	unknown	22:15–05:40 (good, 7.42 h)	89.8° 01:50	8.84	87%	69.7°
2034-09-25 Mon	96	—	unknown	02:15–05:40 (good, 3.42 h)	89.6° 01:45	8.89	94%	59.4°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-09-17&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.