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: 08-09 (100), 08-10 (100), 08-11 (100), 08-12 (100), 08-13 (100) — by astronomy; check the weather when the night is within four days.

2034-08-04astronomy score per night — click a bar for that night2034-09-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-08-04 Fri	48	—	unknown	22:35–04:30 (marginal, 5.92 h)	89.7° 05:10	6.02	76%	38.0°
2034-08-05 Sat	79	—	unknown	23:05–03:15 (good, 4.17 h)	89.6° 05:05	6.07	65%	36.1°
2034-08-06 Sun	85	—	unknown	23:00–04:35 (good, 5.58 h)	89.6° 05:05	6.13	54%	38.8°
2034-08-07 Mon	90	—	unknown	22:55–04:35 (good, 5.67 h)	89.7° 05:00	6.19	42%	45.2°
2034-08-08 Tue	96	—	unknown	22:50–04:35 (good, 5.75 h)	89.8° 04:55	6.24	31%	54.2°
2034-08-09 Wed	100	—	unknown	22:45–04:40 (good, 5.92 h)	89.7° 04:50	6.3	21%	64.5°
2034-08-10 Thu	100	—	unknown	22:45–04:40 (good, 5.92 h)	89.5° 04:45	6.36	13%	75.5°
2034-08-11 Fri	100	—	unknown	22:40–04:40 (good, 6.0 h)	89.6° 04:45	6.42	6%	86.8°
2034-08-12 Sat	100	—	unknown	22:35–04:45 (good, 6.17 h)	89.7° 04:40	6.47	2%	97.9°
2034-08-13 Sun	100	—	unknown	22:30–04:45 (good, 6.25 h)	89.8° 04:35	6.53	0%	108.8°
2034-08-14 Mon	100	—	unknown	22:30–04:45 (good, 6.25 h)	89.6° 04:30	6.59	1%	119.0°
2034-08-15 Tue	100	—	unknown	22:25–04:50 (good, 6.42 h)	89.5° 04:30	6.65	4%	128.2°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-08-04&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.