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: 08-09 (100), 08-10 (100), 08-11 (100), 08-12 (100), 08-13 (100) — by astronomy; check the weather when the night is within four days.

2045-07-26astronomy score per night — click a bar for that night2045-08-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-07-26 Wed	87	—	unknown	00:00–04:15 (good, 4.25 h)	89.8° 05:45	5.55	96%	104.6°
2045-07-27 Thu	78	—	unknown	00:05–04:20 (good, 4.25 h)	89.7° 05:40	5.6	99%	94.2°
2045-07-28 Fri	65	—	unknown	01:00–04:20 (good, 3.33 h)	89.5° 05:40	5.65	100%	83.7°
2045-07-29 Sat	54	—	unknown	02:20–04:20 (good, 2.0 h)	89.7° 05:35	5.71	99%	73.4°
2045-07-30 Sun	44	—	unknown	23:00–04:25 (marginal, 5.42 h)	89.8° 05:30	5.76	96%	63.2°
2045-07-31 Mon	38	—	unknown	23:00–04:25 (marginal, 5.42 h)	89.8° 05:25	5.81	92%	53.4°
2045-08-01 Tue	35	—	unknown	22:55–04:25 (marginal, 5.5 h)	89.6° 05:20	5.87	86%	44.2°
2045-08-02 Wed	37	—	unknown	22:45–04:30 (marginal, 5.75 h)	89.6° 05:20	5.93	79%	36.2°
2045-08-03 Thu	44	—	unknown	22:35–04:30 (marginal, 5.92 h)	89.8° 05:15	5.98	70%	30.5°
2045-08-04 Fri	60	—	unknown	00:15–03:00 (good, 2.75 h)	89.8° 05:10	6.04	61%	28.6°
2045-08-05 Sat	81	—	unknown	23:00–04:35 (good, 5.58 h)	89.7° 05:05	6.09	51%	31.5°
2045-08-06 Sun	85	—	unknown	23:00–04:35 (good, 5.58 h)	89.5° 05:00	6.15	40%	38.6°
2045-08-07 Mon	91	—	unknown	22:55–04:35 (good, 5.67 h)	89.6° 05:00	6.21	30%	48.2°
2045-08-08 Tue	98	—	unknown	22:50–04:35 (good, 5.75 h)	89.8° 04:55	6.26	20%	59.4°
2045-08-09 Wed	100	—	unknown	22:45–04:40 (good, 5.92 h)	89.8° 04:50	6.32	11%	71.7°
2045-08-10 Thu	100	—	unknown	22:45–04:40 (good, 5.92 h)	89.7° 04:45	6.38	5%	84.7°
2045-08-11 Fri	100	—	unknown	22:40–04:40 (good, 6.0 h)	89.5° 04:45	6.44	1%	97.9°
2045-08-12 Sat	100	—	unknown	22:35–04:45 (good, 6.17 h)	89.7° 04:40	6.49	0%	111.2°
2045-08-13 Sun	100	—	unknown	22:30–04:45 (good, 6.25 h)	89.8° 04:35	6.55	2%	124.0°
2045-08-14 Mon	100	—	unknown	22:25–04:45 (good, 6.33 h)	89.8° 04:30	6.61	7%	135.6°
2045-08-15 Tue	100	—	unknown	22:25–04:50 (good, 6.42 h)	89.6° 04:25	6.67	14%	145.2°
2045-08-16 Wed	100	—	unknown	22:20–04:50 (good, 6.5 h)	89.6° 04:25	6.72	24%	150.8°
2045-08-17 Thu	100	—	unknown	22:20–04:50 (good, 6.5 h)	89.7° 04:20	6.78	34%	150.7°
2045-08-18 Fri	100	—	unknown	22:15–04:55 (good, 6.67 h)	89.8° 04:15	6.84	44%	145.4°
2045-08-19 Sat	100	—	unknown	22:10–04:55 (good, 6.75 h)	89.7° 04:10	6.9	55%	137.2°
2045-08-20 Sun	100	—	unknown	22:10–04:55 (good, 6.75 h)	89.5° 04:05	6.95	64%	127.7°
2045-08-21 Mon	100	—	unknown	22:10–04:55 (good, 6.75 h)	89.6° 04:05	7.01	74%	117.6°
2045-08-22 Tue	100	—	unknown	22:10–05:00 (good, 6.83 h)	89.8° 04:00	7.07	82%	107.2°
2045-08-23 Wed	100	—	unknown	22:15–05:00 (good, 6.75 h)	89.8° 03:55	7.13	88%	96.8°
2045-08-24 Thu	100	—	unknown	22:35–05:00 (good, 6.42 h)	89.7° 03:50	7.18	94%	86.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-07-26&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.