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.

2029-07-11astronomy score per night — click a bar for that night2029-08-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-07-11 Wed	89	—	unknown	00:40–03:55 (good, 3.25 h)	89.7° 06:45	4.85	0%	87.1°
2029-07-12 Thu	90	—	unknown	00:35–03:55 (good, 3.33 h)	89.7° 06:40	4.89	2%	98.9°
2029-07-13 Fri	93	—	unknown	00:35–03:55 (good, 3.33 h)	89.7° 06:35	4.93	6%	110.9°
2029-07-14 Sat	96	—	unknown	00:30–04:00 (good, 3.5 h)	89.5° 06:30	4.97	13%	122.6°
2029-07-15 Sun	98	—	unknown	00:25–04:00 (good, 3.58 h)	89.6° 06:30	5.01	21%	133.7°
2029-07-16 Mon	99	—	unknown	00:20–04:00 (good, 3.67 h)	89.7° 06:25	5.05	31%	143.4°
2029-07-17 Tue	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.7° 06:20	5.1	42%	150.0°
2029-07-18 Wed	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.6° 06:15	5.14	54%	151.2°
2029-07-19 Thu	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.5° 06:15	5.19	65%	146.4°
2029-07-20 Fri	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.6° 06:10	5.24	76%	137.7°
2029-07-21 Sat	100	—	unknown	00:10–04:10 (good, 4.0 h)	89.7° 06:05	5.29	85%	127.0°
2029-07-22 Sun	100	—	unknown	00:10–04:10 (good, 4.0 h)	89.7° 06:00	5.34	92%	115.5°
2029-07-23 Mon	83	—	unknown	00:15–04:10 (good, 3.92 h)	89.6° 05:55	5.39	97%	103.7°
2029-07-24 Tue	69	—	unknown	00:35–04:15 (good, 3.67 h)	89.5° 05:55	5.44	100%	91.8°
2029-07-25 Wed	56	—	unknown	01:50–04:15 (good, 2.42 h)	89.7° 05:50	5.49	100%	80.2°
2029-07-26 Thu	45	—	unknown	03:50–04:15 (good, 0.42 h)	89.7° 05:45	5.54	98%	68.9°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-07-11&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.