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.

2045-07-14astronomy score per night — click a bar for that night2045-08-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-07-14 Fri	97	—	unknown	00:30–04:00 (good, 3.5 h)	89.5° 06:35	4.97	0%	90.6°
2045-07-15 Sat	98	—	unknown	00:25–04:00 (good, 3.58 h)	89.7° 06:30	5.02	3%	103.9°
2045-07-16 Sun	99	—	unknown	00:20–04:00 (good, 3.67 h)	89.8° 06:25	5.06	9%	116.8°
2045-07-17 Mon	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.8° 06:20	5.1	17%	128.9°
2045-07-18 Tue	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.6° 06:15	5.15	27%	139.6°
2045-07-19 Wed	100	—	unknown	00:10–04:05 (good, 3.92 h)	89.6° 06:15	5.2	38%	147.7°
2045-07-20 Thu	100	—	unknown	00:05–04:10 (good, 4.08 h)	89.8° 06:10	5.24	48%	151.4°
2045-07-21 Fri	100	—	unknown	00:05–04:10 (good, 4.08 h)	89.8° 06:05	5.29	59%	149.6°
2045-07-22 Sat	100	—	unknown	00:05–04:10 (good, 4.08 h)	89.7° 06:00	5.34	69%	143.4°
2045-07-23 Sun	100	—	unknown	00:00–04:10 (good, 4.17 h)	89.5° 05:55	5.39	78%	134.9°
2045-07-24 Mon	100	—	unknown	00:00–04:15 (good, 4.25 h)	89.6° 05:55	5.44	86%	125.2°
2045-07-25 Tue	100	—	unknown	00:00–04:15 (good, 4.25 h)	89.8° 05:50	5.49	92%	115.0°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-07-14&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.