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: 07-22 (100), 07-23 (100), 07-24 (100), 07-25 (100), 07-26 (100) — by astronomy; check the weather when the night is within four days.

2033-07-18astronomy score per night — click a bar for that night2033-08-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-07-18 Mon	57	—	unknown	00:15–04:05 (good, 3.83 h)	89.6° 06:15	5.15	53%	34.3°
2033-07-19 Tue	76	—	unknown	00:10–04:05 (good, 3.92 h)	89.5° 06:15	5.19	41%	36.4°
2033-07-20 Wed	88	—	unknown	00:05–04:05 (good, 4.0 h)	89.7° 06:10	5.24	31%	42.6°
2033-07-21 Thu	95	—	unknown	00:00–04:10 (good, 4.17 h)	89.8° 06:05	5.29	21%	51.2°
2033-07-22 Fri	100	—	unknown	23:55–04:10 (good, 4.25 h)	89.7° 06:00	5.34	13%	61.2°
2033-07-23 Sat	100	—	unknown	23:55–04:10 (good, 4.25 h)	89.6° 05:55	5.39	6%	71.8°
2033-07-24 Sun	100	—	unknown	23:50–04:15 (good, 4.42 h)	89.6° 05:55	5.44	2%	82.5°
2033-07-25 Mon	100	—	unknown	23:45–04:15 (good, 4.5 h)	89.7° 05:50	5.49	0%	93.2°
2033-07-26 Tue	100	—	unknown	23:40–04:15 (good, 4.58 h)	89.8° 05:45	5.54	0%	103.6°
2033-07-27 Wed	100	—	unknown	23:40–04:20 (good, 4.67 h)	89.7° 05:40	5.59	3%	113.7°
2033-07-28 Thu	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.5° 05:35	5.65	7%	123.1°
2033-07-29 Fri	100	—	unknown	23:30–04:20 (good, 4.83 h)	89.6° 05:35	5.7	12%	131.5°
2033-07-30 Sat	100	—	unknown	23:25–04:25 (good, 5.0 h)	89.7° 05:30	5.76	19%	138.6°
2033-07-31 Sun	100	—	unknown	23:20–04:25 (good, 5.08 h)	89.7° 05:25	5.81	27%	143.6°
2033-08-01 Mon	100	—	unknown	23:20–04:25 (good, 5.08 h)	89.6° 05:20	5.86	36%	145.6°
2033-08-02 Tue	100	—	unknown	23:20–04:30 (good, 5.17 h)	89.5° 05:20	5.92	45%	144.1°
2033-08-03 Wed	100	—	unknown	23:15–04:30 (good, 5.25 h)	89.7° 05:15	5.98	55%	139.4°
2033-08-04 Thu	100	—	unknown	23:15–04:30 (good, 5.25 h)	89.8° 05:10	6.03	64%	132.3°
2033-08-05 Fri	100	—	unknown	23:10–04:30 (good, 5.33 h)	89.7° 05:05	6.09	74%	123.6°
2033-08-06 Sat	100	—	unknown	23:10–04:35 (good, 5.42 h)	89.6° 05:00	6.14	82%	113.8°
2033-08-07 Sun	100	—	unknown	23:15–04:35 (good, 5.33 h)	89.6° 05:00	6.2	90%	103.1°
2033-08-08 Mon	82	—	unknown	23:30–04:35 (good, 5.08 h)	89.7° 04:55	6.26	95%	91.8°
2033-08-09 Tue	73	—	unknown	00:55–04:40 (good, 3.75 h)	89.8° 04:50	6.32	99%	80.2°
2033-08-10 Wed	59	—	unknown	03:25–04:40 (good, 1.25 h)	89.7° 04:45	6.37	100%	68.5°
2033-08-11 Thu	45	—	unknown	22:20–04:40 (marginal, 6.33 h)	89.5° 04:40	6.43	98%	57.2°
2033-08-12 Fri	37	—	unknown	22:15–04:45 (marginal, 6.5 h)	89.6° 04:40	6.49	93%	46.9°
2033-08-13 Sat	40	—	unknown	22:10–04:45 (marginal, 6.58 h)	89.7° 04:35	6.54	86%	38.9°
2033-08-14 Sun	62	—	unknown	22:25–22:40 (good, 0.25 h)	89.7° 04:30	6.6	77%	34.8°
2033-08-15 Mon	82	—	unknown	22:25–02:35 (good, 4.17 h)	89.6° 04:25	6.66	66%	35.7°
2033-08-16 Tue	87	—	unknown	22:20–04:50 (good, 6.5 h)	89.5° 04:25	6.72	55%	41.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-07-18&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.