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: 06-27 (57), 06-26 (55), 06-25 (53), 06-24 (51), 06-23 (50) — by astronomy; check the weather when the night is within four days.

2036-05-29astronomy score per night — click a bar for that night2036-06-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-05-29 Thu	16	—	unknown	03:30–03:50 (good, 0.33 h)	89.5° 09:30	4.89	22%	96.9°
2036-05-30 Fri	17	—	unknown	03:25–03:45 (good, 0.33 h)	89.6° 09:30	4.85	33%	108.1°
2036-05-31 Sat	18	—	unknown	03:20–03:45 (good, 0.42 h)	89.8° 09:25	4.81	44%	118.6°
2036-06-01 Sun	19	—	unknown	03:15–03:45 (good, 0.5 h)	89.8° 09:20	4.78	55%	128.0°
2036-06-02 Mon	21	—	unknown	03:15–03:45 (good, 0.5 h)	89.6° 09:15	4.74	66%	135.6°
2036-06-03 Tue	22	—	unknown	03:15–03:45 (good, 0.5 h)	89.5° 09:15	4.71	76%	140.5°
2036-06-04 Wed	21	—	unknown	03:15–03:40 (good, 0.42 h)	89.7° 09:10	4.68	84%	141.9°
2036-06-05 Thu	21	—	unknown	03:10–03:40 (good, 0.5 h)	89.8° 09:05	4.65	91%	139.6°
2036-06-06 Fri	21	—	unknown	03:10–03:40 (good, 0.5 h)	89.7° 09:00	4.62	96%	134.2°
2036-06-07 Sat	21	—	unknown	03:05–03:40 (good, 0.58 h)	89.6° 08:55	4.59	99%	126.9°
2036-06-08 Sun	22	—	unknown	03:00–03:40 (good, 0.67 h)	89.6° 08:55	4.57	100%	118.5°
2036-06-09 Mon	20	—	unknown	03:05–03:40 (good, 0.58 h)	89.7° 08:50	4.54	99%	109.5°
2036-06-10 Tue	19	—	unknown	03:05–03:40 (good, 0.58 h)	89.8° 08:45	4.52	96%	100.2°
2036-06-11 Wed	18	—	unknown	03:10–03:40 (good, 0.5 h)	89.7° 08:40	4.5	91%	90.8°
2036-06-12 Thu	18	—	unknown	03:25–03:40 (good, 0.25 h)	89.5° 08:35	4.49	85%	81.5°
2036-06-13 Fri	18	—	unknown	03:35–03:40 (good, 0.08 h)	89.6° 08:35	4.47	78%	72.3°
2036-06-14 Sat	19	—	unknown	03:25–03:40 (good, 0.25 h)	89.8° 08:30	4.46	70%	63.5°
2036-06-15 Sun	21	—	unknown	02:50–03:40 (good, 0.83 h)	89.8° 08:25	4.45	61%	55.2°
2036-06-16 Mon	24	—	unknown	02:40–03:40 (good, 1.0 h)	89.6° 08:20	4.44	51%	47.8°
2036-06-17 Tue	28	—	unknown	02:30–03:40 (good, 1.17 h)	89.5° 08:20	4.43	41%	41.9°
2036-06-18 Wed	36	—	unknown	02:10–03:40 (good, 1.5 h)	89.7° 08:15	4.43	31%	38.6°
2036-06-19 Thu	40	—	unknown	02:05–03:40 (good, 1.58 h)	89.8° 08:10	4.42	22%	38.7°
2036-06-20 Fri	44	—	unknown	02:00–03:40 (good, 1.67 h)	89.7° 08:05	4.42	14%	42.5°
2036-06-21 Sat	46	—	unknown	02:00–03:40 (good, 1.67 h)	89.6° 08:00	4.42	7%	49.6°
2036-06-22 Sun	48	—	unknown	01:55–03:40 (good, 1.75 h)	89.6° 08:00	4.43	2%	58.8°
2036-06-23 Mon	50	—	unknown	01:50–03:40 (good, 1.83 h)	89.7° 07:55	4.43	0%	69.5°
2036-06-24 Tue	51	—	unknown	01:45–03:40 (good, 1.92 h)	89.8° 07:50	4.44	1%	81.0°
2036-06-25 Wed	53	—	unknown	01:40–03:40 (good, 2.0 h)	89.7° 07:45	4.45	5%	92.8°
2036-06-26 Thu	55	—	unknown	01:40–03:40 (good, 2.0 h)	89.5° 07:40	4.46	11%	104.5°
2036-06-27 Fri	57	—	unknown	01:35–03:40 (good, 2.08 h)	89.6° 07:40	4.48	20%	115.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-05-29&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.