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), 07-19 (98), 07-18 (94), 07-17 (83), 07-16 (71) — by astronomy; check the weather when the night is within four days.

2047-06-21astronomy score per night — click a bar for that night2047-07-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-06-21 Fri	45	—	unknown	02:00–03:40 (good, 1.67 h)	89.8° 08:05	4.42	2%	52.2°
2047-06-22 Sat	46	—	unknown	01:55–03:40 (good, 1.75 h)	89.7° 08:00	4.42	0%	62.4°
2047-06-23 Sun	48	—	unknown	01:55–03:40 (good, 1.75 h)	89.5° 07:55	4.43	0%	73.2°
2047-06-24 Mon	50	—	unknown	01:50–03:40 (good, 1.83 h)	89.6° 07:55	4.44	2%	84.3°
2047-06-25 Tue	52	—	unknown	01:45–03:40 (good, 1.92 h)	89.8° 07:50	4.44	6%	95.8°
2047-06-26 Wed	53	—	unknown	01:40–03:40 (good, 2.0 h)	89.8° 07:45	4.45	13%	107.3°
2047-06-27 Thu	55	—	unknown	01:40–03:40 (good, 2.0 h)	89.7° 07:40	4.47	21%	118.8°
2047-06-28 Fri	57	—	unknown	01:35–03:40 (good, 2.08 h)	89.5° 07:40	4.48	30%	129.9°
2047-06-29 Sat	59	—	unknown	01:30–03:40 (good, 2.17 h)	89.7° 07:35	4.5	41%	140.1°
2047-06-30 Sun	62	—	unknown	01:25–03:45 (good, 2.33 h)	89.8° 07:30	4.52	52%	148.2°
2047-07-01 Mon	63	—	unknown	01:20–03:45 (good, 2.42 h)	89.8° 07:25	4.54	64%	151.8°
2047-07-02 Tue	65	—	unknown	01:25–03:45 (good, 2.33 h)	89.6° 07:20	4.56	74%	149.2°
2047-07-03 Wed	65	—	unknown	01:20–03:45 (good, 2.42 h)	89.6° 07:20	4.58	84%	141.4°
2047-07-04 Thu	66	—	unknown	01:20–03:45 (good, 2.42 h)	89.8° 07:15	4.61	92%	130.9°
2047-07-05 Fri	59	—	unknown	01:20–03:45 (good, 2.42 h)	89.8° 07:10	4.64	97%	119.1°
2047-07-06 Sat	53	—	unknown	01:25–03:50 (good, 2.42 h)	89.7° 07:05	4.67	100%	106.8°
2047-07-07 Sun	45	—	unknown	01:30–03:50 (good, 2.33 h)	89.6° 07:00	4.7	100%	94.4°
2047-07-08 Mon	38	—	unknown	02:35–03:50 (good, 1.25 h)	89.6° 07:00	4.73	97%	82.3°
2047-07-09 Tue	33	—	unknown	03:40–03:50 (good, 0.17 h)	89.8° 06:55	4.76	92%	70.5°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-06-21&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.