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: 08-06 (100), 08-07 (100), 08-08 (100), 08-09 (100), 08-10 (100) — by astronomy; check the weather when the night is within four days.

2029-07-27astronomy score per night — click a bar for that night2029-08-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-07-27 Fri	37	—	unknown	23:15–04:20 (marginal, 5.08 h)	89.7° 05:40	5.59	94%	58.1°
2029-07-28 Sat	33	—	unknown	23:10–04:20 (marginal, 5.17 h)	89.5° 05:35	5.65	88%	48.2°
2029-07-29 Sun	33	—	unknown	23:05–04:20 (marginal, 5.25 h)	89.6° 05:35	5.7	81%	39.4°
2029-07-30 Mon	38	—	unknown	22:55–04:25 (marginal, 5.5 h)	89.7° 05:30	5.75	73%	32.6°
2029-07-31 Tue	48	—	unknown	22:50–04:25 (marginal, 5.58 h)	89.7° 05:25	5.81	64%	28.9°
2029-08-01 Wed	69	—	unknown	23:45–04:25 (good, 4.67 h)	89.6° 05:20	5.86	55%	29.4°
2029-08-02 Thu	83	—	unknown	23:15–04:30 (good, 5.25 h)	89.5° 05:20	5.92	46%	34.0°
2029-08-03 Fri	87	—	unknown	23:10–04:30 (good, 5.33 h)	89.6° 05:15	5.97	36%	41.3°
2029-08-04 Sat	93	—	unknown	23:05–04:30 (good, 5.42 h)	89.7° 05:10	6.03	27%	50.4°
2029-08-05 Sun	99	—	unknown	23:00–04:30 (good, 5.5 h)	89.7° 05:05	6.09	19%	60.5°
2029-08-06 Mon	100	—	unknown	23:00–04:35 (good, 5.58 h)	89.6° 05:00	6.14	11%	71.4°
2029-08-07 Tue	100	—	unknown	22:55–04:35 (good, 5.67 h)	89.5° 05:00	6.2	6%	82.8°
2029-08-08 Wed	100	—	unknown	22:50–04:35 (good, 5.75 h)	89.7° 04:55	6.26	2%	94.7°
2029-08-09 Thu	100	—	unknown	22:45–04:40 (good, 5.92 h)	89.7° 04:50	6.31	0%	106.8°
2029-08-10 Fri	100	—	unknown	22:40–04:40 (good, 6.0 h)	89.7° 04:45	6.37	1%	118.8°
2029-08-11 Sat	100	—	unknown	22:40–04:40 (good, 6.0 h)	89.5° 04:40	6.43	5%	130.5°
2029-08-12 Sun	100	—	unknown	22:35–04:45 (good, 6.17 h)	89.6° 04:40	6.49	11%	140.9°
2029-08-13 Mon	100	—	unknown	22:30–04:45 (good, 6.25 h)	89.7° 04:35	6.54	19%	148.6°
2029-08-14 Tue	100	—	unknown	22:25–04:45 (good, 6.33 h)	89.7° 04:30	6.6	29%	151.3°
2029-08-15 Wed	100	—	unknown	22:25–04:50 (good, 6.42 h)	89.6° 04:25	6.66	40%	147.8°
2029-08-16 Thu	100	—	unknown	22:25–04:50 (good, 6.42 h)	89.5° 04:25	6.72	52%	139.8°
2029-08-17 Fri	100	—	unknown	22:20–04:50 (good, 6.5 h)	89.6° 04:20	6.77	63%	129.6°
2029-08-18 Sat	100	—	unknown	22:20–04:50 (good, 6.5 h)	89.7° 04:15	6.83	73%	118.4°
2029-08-19 Sun	100	—	unknown	22:25–04:55 (good, 6.5 h)	89.7° 04:10	6.89	82%	106.8°
2029-08-20 Mon	100	—	unknown	22:30–04:55 (good, 6.42 h)	89.6° 04:05	6.95	90%	95.2°
2029-08-21 Tue	100	—	unknown	23:20–04:55 (good, 5.58 h)	89.5° 04:05	7.0	95%	83.7°
2029-08-22 Wed	72	—	unknown	01:00–05:00 (good, 4.0 h)	89.7° 04:00	7.06	98%	72.4°
2029-08-23 Thu	62	—	unknown	04:35–05:00 (good, 0.42 h)	89.7° 03:55	7.12	100%	61.6°
2029-08-24 Fri	46	—	unknown	21:50–05:00 (marginal, 7.17 h)	89.7° 03:50	7.17	99%	51.4°
2029-08-25 Sat	35	—	unknown	21:50–05:05 (marginal, 7.25 h)	89.5° 03:45	7.23	96%	42.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-07-27&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.