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: 07-17 (100), 07-18 (100), 07-19 (100), 07-20 (100), 07-21 (100) — by astronomy; check the weather when the night is within four days.

2045-06-26astronomy score per night — click a bar for that night2045-07-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-06-26 Mon	47	—	unknown	01:50–03:40 (good, 1.83 h)	89.7° 07:45	4.46	94%	132.6°
2045-06-27 Tue	47	—	unknown	01:45–03:40 (good, 1.92 h)	89.8° 07:40	4.47	98%	122.7°
2045-06-28 Wed	44	—	unknown	01:50–03:40 (good, 1.83 h)	89.8° 07:35	4.49	100%	112.4°
2045-06-29 Thu	40	—	unknown	01:50–03:45 (good, 1.92 h)	89.6° 07:30	4.51	100%	102.0°
2045-06-30 Fri	36	—	unknown	01:55–03:45 (good, 1.83 h)	89.5° 07:30	4.53	98%	91.5°
2045-07-01 Sat	32	—	unknown	02:45–03:45 (good, 1.0 h)	89.7° 07:25	4.55	94%	81.0°
2045-07-02 Sun	29	—	unknown	03:35–03:45 (good, 0.17 h)	89.8° 07:20	4.57	88%	70.7°
2045-07-03 Mon	28	—	unknown	00:40–03:45 (marginal, 3.08 h)	89.8° 07:15	4.59	82%	60.7°
2045-07-04 Tue	28	—	unknown	00:35–03:45 (marginal, 3.17 h)	89.6° 07:10	4.62	74%	51.0°
2045-07-05 Wed	31	—	unknown	00:30–03:50 (marginal, 3.33 h)	89.6° 07:10	4.65	65%	42.0°
2045-07-06 Thu	36	—	unknown	01:50–03:50 (good, 2.0 h)	89.8° 07:05	4.68	55%	34.4°
2045-07-07 Fri	43	—	unknown	01:20–03:50 (good, 2.5 h)	89.8° 07:00	4.71	45%	29.5°
2045-07-08 Sat	54	—	unknown	00:50–03:50 (good, 3.0 h)	89.7° 06:55	4.74	35%	29.1°
2045-07-09 Sun	65	—	unknown	00:50–03:50 (good, 3.0 h)	89.5° 06:50	4.78	26%	33.6°
2045-07-10 Mon	77	—	unknown	00:45–03:55 (good, 3.17 h)	89.7° 06:50	4.81	17%	41.9°
2045-07-11 Tue	85	—	unknown	00:40–03:55 (good, 3.25 h)	89.8° 06:45	4.85	9%	52.6°
2045-07-12 Wed	90	—	unknown	00:35–03:55 (good, 3.33 h)	89.8° 06:40	4.89	3%	64.6°
2045-07-13 Thu	94	—	unknown	00:35–04:00 (good, 3.42 h)	89.6° 06:35	4.93	0%	77.4°
2045-07-14 Fri	97	—	unknown	00:30–04:00 (good, 3.5 h)	89.5° 06:35	4.97	0%	90.6°
2045-07-15 Sat	98	—	unknown	00:25–04:00 (good, 3.58 h)	89.7° 06:30	5.02	3%	103.9°
2045-07-16 Sun	99	—	unknown	00:20–04:00 (good, 3.67 h)	89.8° 06:25	5.06	9%	116.8°
2045-07-17 Mon	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.8° 06:20	5.1	17%	128.9°
2045-07-18 Tue	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.6° 06:15	5.15	27%	139.6°
2045-07-19 Wed	100	—	unknown	00:10–04:05 (good, 3.92 h)	89.6° 06:15	5.2	38%	147.7°
2045-07-20 Thu	100	—	unknown	00:05–04:10 (good, 4.08 h)	89.8° 06:10	5.24	48%	151.4°
2045-07-21 Fri	100	—	unknown	00:05–04:10 (good, 4.08 h)	89.8° 06:05	5.29	59%	149.6°
2045-07-22 Sat	100	—	unknown	00:05–04:10 (good, 4.08 h)	89.7° 06:00	5.34	69%	143.4°
2045-07-23 Sun	100	—	unknown	00:00–04:10 (good, 4.17 h)	89.5° 05:55	5.39	78%	134.9°
2045-07-24 Mon	100	—	unknown	00:00–04:15 (good, 4.25 h)	89.6° 05:55	5.44	86%	125.2°
2045-07-25 Tue	100	—	unknown	00:00–04:15 (good, 4.25 h)	89.8° 05:50	5.49	92%	115.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-06-26&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.