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: 07-30 (100), 07-31 (100), 08-01 (100), 08-02 (100), 08-03 (100) — by astronomy; check the weather when the night is within four days.

2046-07-10astronomy score per night — click a bar for that night2046-08-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-07-10 Tue	86	—	unknown	00:45–03:55 (good, 3.17 h)	89.8° 06:50	4.81	51%	150.9°
2046-07-11 Wed	87	—	unknown	00:45–03:55 (good, 3.17 h)	89.8° 06:45	4.84	62%	151.3°
2046-07-12 Thu	88	—	unknown	00:45–03:55 (good, 3.17 h)	89.7° 06:40	4.88	73%	146.0°
2046-07-13 Fri	89	—	unknown	00:40–03:55 (good, 3.25 h)	89.5° 06:40	4.92	82%	137.3°
2046-07-14 Sat	91	—	unknown	00:40–04:00 (good, 3.33 h)	89.7° 06:35	4.96	90%	127.0°
2046-07-15 Sun	88	—	unknown	00:40–04:00 (good, 3.33 h)	89.8° 06:30	5.01	95%	115.9°
2046-07-16 Mon	70	—	unknown	00:45–04:00 (good, 3.25 h)	89.8° 06:25	5.05	99%	104.7°
2046-07-17 Tue	60	—	unknown	00:50–04:05 (good, 3.25 h)	89.6° 06:20	5.09	100%	93.5°
2046-07-18 Wed	51	—	unknown	01:55–04:05 (good, 2.17 h)	89.6° 06:20	5.14	99%	82.4°
2046-07-19 Thu	42	—	unknown	03:05–04:05 (good, 1.0 h)	89.8° 06:15	5.19	96%	71.6°
2046-07-20 Fri	36	—	unknown	23:40–04:05 (marginal, 4.42 h)	89.8° 06:10	5.23	92%	61.1°
2046-07-21 Sat	33	—	unknown	23:40–04:10 (marginal, 4.5 h)	89.7° 06:05	5.28	86%	51.3°
2046-07-22 Sun	33	—	unknown	23:30–04:10 (marginal, 4.67 h)	89.5° 06:00	5.33	79%	42.2°
2046-07-23 Mon	37	—	unknown	23:25–04:10 (marginal, 4.75 h)	89.6° 06:00	5.38	70%	34.6°
2046-07-24 Tue	45	—	unknown	23:15–04:15 (marginal, 5.0 h)	89.8° 05:55	5.43	62%	29.5°
2046-07-25 Wed	58	—	unknown	00:15–04:15 (good, 4.0 h)	89.8° 05:50	5.48	52%	28.2°
2046-07-26 Thu	79	—	unknown	23:45–04:15 (good, 4.5 h)	89.7° 05:45	5.53	42%	31.5°
2046-07-27 Fri	85	—	unknown	23:40–04:20 (good, 4.67 h)	89.5° 05:45	5.59	33%	38.3°
2046-07-28 Sat	91	—	unknown	23:35–04:20 (good, 4.75 h)	89.7° 05:40	5.64	23%	47.4°
2046-07-29 Sun	97	—	unknown	23:30–04:20 (good, 4.83 h)	89.8° 05:35	5.69	15%	58.0°
2046-07-30 Mon	100	—	unknown	23:25–04:25 (good, 5.0 h)	89.8° 05:30	5.75	8%	69.5°
2046-07-31 Tue	100	—	unknown	23:25–04:25 (good, 5.0 h)	89.6° 05:25	5.8	3%	81.7°
2046-08-01 Wed	100	—	unknown	23:20–04:25 (good, 5.08 h)	89.6° 05:25	5.86	0%	94.3°
2046-08-02 Thu	100	—	unknown	23:15–04:25 (good, 5.17 h)	89.7° 05:20	5.91	0%	107.1°
2046-08-03 Fri	100	—	unknown	23:10–04:30 (good, 5.33 h)	89.8° 05:15	5.97	3%	119.8°
2046-08-04 Sat	100	—	unknown	23:05–04:30 (good, 5.42 h)	89.7° 05:10	6.02	9%	131.8°
2046-08-05 Sun	100	—	unknown	23:05–04:30 (good, 5.42 h)	89.6° 05:05	6.08	17%	142.4°
2046-08-06 Mon	100	—	unknown	23:00–04:35 (good, 5.58 h)	89.6° 05:05	6.14	27%	149.8°
2046-08-07 Tue	100	—	unknown	22:55–04:35 (good, 5.67 h)	89.8° 05:00	6.19	37%	151.8°
2046-08-08 Wed	100	—	unknown	22:55–04:35 (good, 5.67 h)	89.8° 04:55	6.25	49%	147.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-07-10&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.