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: 07-20 (100), 07-21 (100), 07-22 (100), 07-23 (100), 07-24 (100) — by astronomy; check the weather when the night is within four days.

2047-07-10astronomy score per night — click a bar for that night2047-08-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-07-10 Wed	30	—	unknown	00:20–03:55 (marginal, 3.58 h)	89.8° 06:50	4.8	86%	59.4°
2047-07-11 Thu	29	—	unknown	00:15–03:55 (marginal, 3.67 h)	89.7° 06:45	4.83	78%	49.1°
2047-07-12 Fri	32	—	unknown	00:10–03:55 (marginal, 3.75 h)	89.5° 06:45	4.87	70%	40.0°
2047-07-13 Sat	37	—	unknown	03:45–03:55 (good, 0.17 h)	89.7° 06:40	4.91	60%	32.8°
2047-07-14 Sun	46	—	unknown	01:00–04:00 (good, 3.0 h)	89.8° 06:35	4.95	51%	28.7°
2047-07-15 Mon	58	—	unknown	00:25–04:00 (good, 3.58 h)	89.8° 06:30	5.0	41%	28.8°
2047-07-16 Tue	71	—	unknown	00:25–04:00 (good, 3.58 h)	89.6° 06:25	5.04	32%	33.1°
2047-07-17 Wed	83	—	unknown	00:20–04:00 (good, 3.67 h)	89.6° 06:25	5.08	24%	40.2°
2047-07-18 Thu	94	—	unknown	00:15–04:05 (good, 3.83 h)	89.7° 06:20	5.13	16%	49.1°
2047-07-19 Fri	98	—	unknown	00:10–04:05 (good, 3.92 h)	89.8° 06:15	5.17	9%	59.1°
2047-07-20 Sat	100	—	unknown	00:05–04:05 (good, 4.0 h)	89.7° 06:10	5.22	4%	69.7°
2047-07-21 Sun	100	—	unknown	00:05–04:10 (good, 4.08 h)	89.6° 06:05	5.27	1%	80.9°
2047-07-22 Mon	100	—	unknown	00:00–04:10 (good, 4.17 h)	89.6° 06:05	5.32	0%	92.4°
2047-07-23 Tue	100	—	unknown	23:55–04:10 (good, 4.25 h)	89.8° 06:00	5.37	1%	104.1°
2047-07-24 Wed	100	—	unknown	23:50–04:15 (good, 4.42 h)	89.8° 05:55	5.42	5%	115.8°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-07-10&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.