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: 07-25 (100), 07-26 (100), 07-27 (100), 07-28 (100), 07-29 (100) — by astronomy; check the weather when the night is within four days.

2047-07-25astronomy score per night — click a bar for that night2047-08-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-07-25 Thu	100	—	unknown	23:45–04:15 (good, 4.5 h)	89.7° 05:50	5.47	10%	127.3°
2047-07-26 Fri	100	—	unknown	23:45–04:15 (good, 4.5 h)	89.5° 05:50	5.52	18%	137.9°
2047-07-27 Sat	100	—	unknown	23:40–04:20 (good, 4.67 h)	89.7° 05:45	5.57	28%	146.6°
2047-07-28 Sun	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.8° 05:40	5.63	39%	151.5°
2047-07-29 Mon	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.8° 05:35	5.68	50%	150.3°
2047-07-30 Tue	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.6° 05:30	5.73	62%	143.7°
2047-07-31 Wed	100	—	unknown	23:30–04:25 (good, 4.92 h)	89.6° 05:30	5.79	72%	133.9°
2047-08-01 Thu	100	—	unknown	23:30–04:25 (good, 4.92 h)	89.7° 05:25	5.84	82%	122.7°
2047-08-02 Fri	100	—	unknown	23:30–04:25 (good, 4.92 h)	89.8° 05:20	5.9	90%	110.8°
2047-08-03 Sat	100	—	unknown	23:40–04:30 (good, 4.83 h)	89.7° 05:15	5.95	96%	98.7°
2047-08-04 Sun	77	—	unknown	00:20–04:30 (good, 4.17 h)	89.6° 05:10	6.01	99%	86.7°
2047-08-05 Mon	62	—	unknown	01:50–04:30 (good, 2.67 h)	89.6° 05:10	6.07	100%	74.9°
2047-08-06 Tue	49	—	unknown	22:40–04:35 (marginal, 5.92 h)	89.8° 05:05	6.12	99%	63.5°
2047-08-07 Wed	38	—	unknown	22:40–04:35 (marginal, 5.92 h)	89.8° 05:00	6.18	95%	52.8°
2047-08-08 Thu	34	—	unknown	22:35–04:35 (marginal, 6.0 h)	89.7° 04:55	6.24	90%	43.2°
2047-08-09 Fri	36	—	unknown	22:25–04:40 (marginal, 6.25 h)	89.5° 04:50	6.29	83%	35.1°
2047-08-10 Sat	42	—	unknown	22:20–04:40 (marginal, 6.33 h)	89.7° 04:50	6.35	75%	29.7°
2047-08-11 Sun	61	—	unknown	22:40–22:50 (good, 0.17 h)	89.8° 04:45	6.41	67%	28.4°
2047-08-12 Mon	80	—	unknown	22:35–03:55 (good, 5.33 h)	89.8° 04:40	6.47	57%	31.4°
2047-08-13 Tue	85	—	unknown	22:35–04:45 (good, 6.17 h)	89.6° 04:35	6.52	48%	37.7°
2047-08-14 Wed	90	—	unknown	22:30–04:45 (good, 6.25 h)	89.6° 04:35	6.58	39%	46.0°
2047-08-15 Thu	96	—	unknown	22:25–04:45 (good, 6.33 h)	89.7° 04:30	6.64	30%	55.5°
2047-08-16 Fri	100	—	unknown	22:20–04:50 (good, 6.5 h)	89.8° 04:25	6.7	21%	65.9°
2047-08-17 Sat	100	—	unknown	22:15–04:50 (good, 6.58 h)	89.7° 04:20	6.75	13%	76.8°
2047-08-18 Sun	100	—	unknown	22:15–04:50 (good, 6.58 h)	89.6° 04:15	6.81	7%	88.2°
2047-08-19 Mon	100	—	unknown	22:10–04:55 (good, 6.75 h)	89.6° 04:15	6.87	3%	99.9°
2047-08-20 Tue	100	—	unknown	22:05–04:55 (good, 6.83 h)	89.8° 04:10	6.93	0%	111.7°
2047-08-21 Wed	100	—	unknown	22:00–04:55 (good, 6.92 h)	89.8° 04:05	6.98	0%	123.5°
2047-08-22 Thu	100	—	unknown	21:55–05:00 (good, 7.08 h)	89.7° 04:00	7.04	3%	134.7°
2047-08-23 Fri	100	—	unknown	21:55–05:00 (good, 7.08 h)	89.5° 03:55	7.1	9%	144.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-07-25&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.