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: 08-16 (100), 08-17 (100), 08-18 (100), 08-19 (100), 08-20 (100) — by astronomy; check the weather when the night is within four days.

2034-08-16astronomy score per night — click a bar for that night2034-09-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-08-16 Wed	100	—	unknown	22:20–04:50 (good, 6.5 h)	89.7° 04:25	6.7	8%	135.9°
2034-08-17 Thu	100	—	unknown	22:15–04:50 (good, 6.58 h)	89.8° 04:20	6.76	15%	141.3°
2034-08-18 Fri	100	—	unknown	22:15–04:50 (good, 6.58 h)	89.7° 04:15	6.82	22%	143.8°
2034-08-19 Sat	100	—	unknown	22:10–04:55 (good, 6.75 h)	89.6° 04:10	6.88	31%	142.8°
2034-08-20 Sun	100	—	unknown	22:10–04:55 (good, 6.75 h)	89.5° 04:10	6.93	40%	138.8°
2034-08-21 Mon	100	—	unknown	22:05–04:55 (good, 6.83 h)	89.7° 04:05	6.99	49%	132.5°
2034-08-22 Tue	100	—	unknown	22:05–05:00 (good, 6.92 h)	89.8° 04:00	7.05	58%	124.8°
2034-08-23 Wed	100	—	unknown	22:00–05:00 (good, 7.0 h)	89.7° 03:55	7.11	68%	116.0°
2034-08-24 Thu	100	—	unknown	22:05–05:00 (good, 6.92 h)	89.5° 03:50	7.16	77%	106.6°
2034-08-25 Fri	100	—	unknown	22:10–05:00 (good, 6.83 h)	89.6° 03:50	7.22	84%	96.7°
2034-08-26 Sat	100	—	unknown	22:40–05:05 (good, 6.42 h)	89.7° 03:45	7.28	91%	86.4°
2034-08-27 Sun	77	—	unknown	00:00–05:05 (good, 5.08 h)	89.8° 03:40	7.33	96%	75.9°
2034-08-28 Mon	67	—	unknown	03:05–05:05 (good, 2.0 h)	89.6° 03:35	7.39	99%	65.4°
2034-08-29 Tue	57	—	unknown	21:40–05:10 (marginal, 7.5 h)	89.5° 03:35	7.45	100%	55.3°
2034-08-30 Wed	44	—	unknown	21:40–05:10 (marginal, 7.5 h)	89.6° 03:30	7.5	98%	46.3°
2034-08-31 Thu	43	—	unknown	21:35–05:10 (marginal, 7.58 h)	89.8° 03:25	7.56	94%	39.4°
2034-09-01 Fri	71	—	unknown	21:35–21:40 (good, 0.08 h)	89.7° 03:20	7.61	87%	36.2°
2034-09-02 Sat	84	—	unknown	21:35–22:20 (good, 0.75 h)	89.6° 03:15	7.67	78%	37.8°
2034-09-03 Sun	89	—	unknown	21:30–03:00 (good, 5.5 h)	89.5° 03:15	7.73	68%	43.6°
2034-09-04 Mon	94	—	unknown	21:30–05:15 (good, 7.75 h)	89.7° 03:10	7.78	56%	52.1°
2034-09-05 Tue	100	—	unknown	21:25–05:15 (good, 7.83 h)	89.8° 03:05	7.84	45%	62.1°
2034-09-06 Wed	100	—	unknown	21:25–05:20 (good, 7.92 h)	89.7° 03:00	7.89	34%	72.8°
2034-09-07 Thu	100	—	unknown	21:25–05:20 (good, 7.92 h)	89.5° 02:55	7.95	24%	83.8°
2034-09-08 Fri	100	—	unknown	21:20–05:20 (good, 8.0 h)	89.6° 02:55	8.0	15%	94.8°
2034-09-09 Sat	100	—	unknown	21:20–05:25 (good, 8.08 h)	89.7° 02:50	8.05	8%	105.5°
2034-09-10 Sun	100	—	unknown	21:15–05:25 (good, 8.17 h)	89.8° 02:45	8.11	3%	115.8°
2034-09-11 Mon	100	—	unknown	21:15–05:25 (good, 8.17 h)	89.6° 02:40	8.16	1%	125.3°
2034-09-12 Tue	100	—	unknown	21:15–05:25 (good, 8.17 h)	89.5° 02:40	8.22	0%	133.5°
2034-09-13 Wed	100	—	unknown	21:10–05:30 (good, 8.33 h)	89.6° 02:35	8.27	2%	139.8°
2034-09-14 Thu	100	—	unknown	21:10–05:30 (good, 8.33 h)	89.8° 02:30	8.32	5%	143.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-08-16&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.