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: 08-28 (100), 08-29 (100), 08-30 (100), 08-31 (100), 09-01 (100) — by astronomy; check the weather when the night is within four days.

2044-08-28astronomy score per night — click a bar for that night2044-09-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-08-28 Sun	100	—	unknown	21:40–05:05 (good, 7.42 h)	89.8° 03:35	7.42	36%	145.0°
2044-08-29 Mon	100	—	unknown	21:40–05:10 (good, 7.5 h)	89.8° 03:30	7.48	46%	137.5°
2044-08-30 Tue	100	—	unknown	21:40–05:10 (good, 7.5 h)	89.6° 03:25	7.54	55%	128.7°
2044-08-31 Wed	100	—	unknown	21:35–05:10 (good, 7.58 h)	89.6° 03:25	7.59	64%	119.1°
2044-09-01 Thu	100	—	unknown	21:35–05:15 (good, 7.67 h)	89.7° 03:20	7.65	73%	109.2°
2044-09-02 Fri	100	—	unknown	21:30–05:15 (good, 7.75 h)	89.8° 03:15	7.7	81%	98.9°
2044-09-03 Sat	100	—	unknown	21:35–05:15 (good, 7.67 h)	89.7° 03:10	7.76	88%	88.5°
2044-09-04 Sun	100	—	unknown	22:40–05:15 (good, 6.58 h)	89.5° 03:05	7.81	94%	78.0°
2044-09-05 Mon	73	—	unknown	01:00–05:20 (good, 4.33 h)	89.6° 03:05	7.87	98%	67.5°
2044-09-06 Tue	63	—	unknown	04:45–05:20 (good, 0.58 h)	89.8° 03:00	7.92	100%	57.1°
2044-09-07 Wed	51	—	unknown	21:20–05:20 (marginal, 8.0 h)	89.8° 02:55	7.98	100%	47.2°
2044-09-08 Thu	38	—	unknown	21:20–05:20 (marginal, 8.0 h)	89.7° 02:50	8.03	98%	38.3°
2044-09-09 Fri	38	—	unknown	21:20–05:25 (marginal, 8.08 h)	89.5° 02:50	8.09	94%	31.8°
2044-09-10 Sat	46	—	unknown	21:15–05:25 (marginal, 8.17 h)	89.7° 02:45	8.14	87%	29.5°
2044-09-11 Sun	81	—	unknown	21:15–21:20 (good, 0.08 h)	89.8° 02:40	8.19	79%	32.5°
2044-09-12 Mon	85	—	unknown	21:10–01:25 (good, 4.25 h)	89.8° 02:35	8.25	69%	39.8°
2044-09-13 Tue	91	—	unknown	21:10–05:30 (good, 8.33 h)	89.6° 02:30	8.3	58%	49.7°
2044-09-14 Wed	98	—	unknown	21:10–05:30 (good, 8.33 h)	89.6° 02:30	8.35	47%	61.0°
2044-09-15 Thu	100	—	unknown	21:05–05:30 (good, 8.42 h)	89.7° 02:25	8.41	36%	73.0°
2044-09-16 Fri	100	—	unknown	21:05–05:30 (good, 8.42 h)	89.8° 02:20	8.46	25%	85.3°
2044-09-17 Sat	100	—	unknown	21:05–05:35 (good, 8.5 h)	89.7° 02:15	8.51	16%	97.8°
2044-09-18 Sun	100	—	unknown	21:00–05:35 (good, 8.58 h)	89.6° 02:10	8.56	8%	110.2°
2044-09-19 Mon	100	—	unknown	21:00–05:35 (good, 8.58 h)	89.6° 02:10	8.61	3%	122.1°
2044-09-20 Tue	100	—	unknown	20:55–05:35 (good, 8.67 h)	89.8° 02:05	8.67	0%	133.1°
2044-09-21 Wed	100	—	unknown	20:55–05:40 (good, 8.75 h)	89.8° 02:00	8.72	0%	142.4°
2044-09-22 Thu	100	—	unknown	20:55–05:40 (good, 8.75 h)	89.7° 01:55	8.77	3%	148.8°
2044-09-23 Fri	100	—	unknown	20:50–05:40 (good, 8.83 h)	89.5° 01:55	8.82	7%	150.4°
2044-09-24 Sat	100	—	unknown	20:50–05:40 (good, 8.83 h)	89.7° 01:50	8.87	13%	147.1°
2044-09-25 Sun	100	—	unknown	20:50–05:45 (good, 8.92 h)	89.8° 01:45	8.92	21%	140.4°
2044-09-26 Mon	100	—	unknown	20:45–05:45 (good, 9.0 h)	89.8° 01:40	8.97	29%	131.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-08-28&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.