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: 07-02 (62), 07-01 (61), 06-30 (60), 06-29 (59), 06-28 (57) — by astronomy; check the weather when the night is within four days.

2039-06-08astronomy score per night — click a bar for that night2039-07-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-06-08 Wed	17	—	unknown	03:15–03:40 (good, 0.42 h)	89.7° 08:55	4.58	93%	99.4°
2039-06-09 Thu	17	—	unknown	03:15–03:40 (good, 0.42 h)	89.6° 08:50	4.56	86%	87.8°
2039-06-10 Fri	17	—	unknown	03:15–03:40 (good, 0.42 h)	89.6° 08:50	4.54	77%	76.7°
2039-06-11 Sat	18	—	unknown	03:10–03:40 (good, 0.5 h)	89.7° 08:45	4.52	67%	66.3°
2039-06-12 Sun	19	—	unknown	03:00–03:40 (good, 0.67 h)	89.8° 08:40	4.5	57%	56.8°
2039-06-13 Mon	22	—	unknown	02:50–03:40 (good, 0.83 h)	89.7° 08:35	4.48	47%	48.6°
2039-06-14 Tue	26	—	unknown	02:30–03:40 (good, 1.17 h)	89.5° 08:30	4.47	37%	42.3°
2039-06-15 Wed	33	—	unknown	02:25–03:40 (good, 1.25 h)	89.7° 08:30	4.45	28%	38.4°
2039-06-16 Thu	36	—	unknown	02:20–03:40 (good, 1.33 h)	89.8° 08:25	4.44	19%	37.7°
2039-06-17 Fri	39	—	unknown	02:15–03:40 (good, 1.42 h)	89.8° 08:20	4.44	12%	40.1°
2039-06-18 Sat	40	—	unknown	02:15–03:40 (good, 1.42 h)	89.6° 08:15	4.43	7%	45.1°
2039-06-19 Sun	42	—	unknown	02:10–03:40 (good, 1.5 h)	89.5° 08:15	4.42	3%	51.9°
2039-06-20 Mon	44	—	unknown	02:05–03:40 (good, 1.58 h)	89.7° 08:10	4.42	1%	59.9°
2039-06-21 Tue	45	—	unknown	02:00–03:40 (good, 1.67 h)	89.8° 08:05	4.42	0%	68.6°
2039-06-22 Wed	46	—	unknown	01:55–03:40 (good, 1.75 h)	89.7° 08:00	4.42	1%	77.8°
2039-06-23 Thu	48	—	unknown	01:55–03:40 (good, 1.75 h)	89.6° 07:55	4.43	4%	87.4°
2039-06-24 Fri	50	—	unknown	01:50–03:40 (good, 1.83 h)	89.6° 07:55	4.43	10%	97.1°
2039-06-25 Sat	52	—	unknown	01:45–03:40 (good, 1.92 h)	89.7° 07:50	4.44	16%	106.8°
2039-06-26 Sun	53	—	unknown	01:40–03:40 (good, 2.0 h)	89.8° 07:45	4.45	24%	116.4°
2039-06-27 Mon	55	—	unknown	01:35–03:40 (good, 2.08 h)	89.7° 07:40	4.47	34%	125.4°
2039-06-28 Tue	57	—	unknown	01:35–03:40 (good, 2.08 h)	89.5° 07:35	4.48	44%	133.5°
2039-06-29 Wed	59	—	unknown	01:35–03:40 (good, 2.08 h)	89.6° 07:35	4.5	55%	139.5°
2039-06-30 Thu	60	—	unknown	01:30–03:45 (good, 2.25 h)	89.8° 07:30	4.51	66%	142.4°
2039-07-01 Fri	61	—	unknown	01:30–03:45 (good, 2.25 h)	89.8° 07:25	4.53	77%	140.8°
2039-07-02 Sat	62	—	unknown	01:25–03:45 (good, 2.33 h)	89.6° 07:20	4.56	86%	135.1°
2039-07-03 Sun	57	—	unknown	01:25–03:45 (good, 2.33 h)	89.5° 07:20	4.58	93%	126.4°
2039-07-04 Mon	55	—	unknown	01:25–03:45 (good, 2.33 h)	89.7° 07:15	4.61	98%	115.9°
2039-07-05 Tue	49	—	unknown	01:30–03:45 (good, 2.25 h)	89.8° 07:10	4.63	100%	104.5°
2039-07-06 Wed	43	—	unknown	01:30–03:50 (good, 2.33 h)	89.7° 07:05	4.66	99%	92.8°
2039-07-07 Thu	38	—	unknown	02:15–03:50 (good, 1.58 h)	89.6° 07:00	4.69	95%	81.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-06-08&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.