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: 06-25 (53), 06-24 (50), 06-23 (48), 06-22 (45), 06-21 (39) — by astronomy; check the weather when the night is within four days.

2033-05-27astronomy score per night — click a bar for that night2033-06-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-05-27 Fri	14	—	unknown	03:35–03:50 (good, 0.25 h)	89.7° 09:40	4.98	0%	47.3°
2033-05-28 Sat	15	—	unknown	03:35–03:50 (good, 0.25 h)	89.5° 09:35	4.94	0%	57.3°
2033-05-29 Sun	16	—	unknown	03:30–03:50 (good, 0.33 h)	89.6° 09:35	4.9	3%	68.1°
2033-05-30 Mon	17	—	unknown	03:25–03:45 (good, 0.33 h)	89.7° 09:30	4.86	8%	79.1°
2033-05-31 Tue	18	—	unknown	03:20–03:45 (good, 0.42 h)	89.7° 09:25	4.82	14%	90.0°
2033-06-01 Wed	19	—	unknown	03:20–03:45 (good, 0.42 h)	89.6° 09:20	4.79	22%	100.6°
2033-06-02 Thu	21	—	unknown	03:15–03:45 (good, 0.5 h)	89.5° 09:20	4.75	31%	110.7°
2033-06-03 Fri	23	—	unknown	03:10–03:45 (good, 0.58 h)	89.6° 09:15	4.72	40%	120.3°
2033-06-04 Sat	23	—	unknown	03:05–03:45 (good, 0.67 h)	89.8° 09:10	4.68	50%	129.1°
2033-06-05 Sun	24	—	unknown	03:00–03:40 (good, 0.67 h)	89.7° 09:05	4.65	59%	136.7°
2033-06-06 Mon	25	—	unknown	03:00–03:40 (good, 0.67 h)	89.6° 09:00	4.63	68%	142.6°
2033-06-07 Tue	26	—	unknown	03:00–03:40 (good, 0.67 h)	89.5° 09:00	4.6	76%	145.8°
2033-06-08 Wed	27	—	unknown	03:00–03:40 (good, 0.67 h)	89.7° 08:55	4.57	84%	145.4°
2033-06-09 Thu	25	—	unknown	02:55–03:40 (good, 0.75 h)	89.8° 08:50	4.55	91%	141.6°
2033-06-10 Fri	25	—	unknown	02:55–03:40 (good, 0.75 h)	89.7° 08:45	4.53	96%	134.9°
2033-06-11 Sat	25	—	unknown	02:50–03:40 (good, 0.83 h)	89.5° 08:40	4.51	99%	126.4°
2033-06-12 Sun	25	—	unknown	02:50–03:40 (good, 0.83 h)	89.6° 08:40	4.49	100%	116.6°
2033-06-13 Mon	23	—	unknown	02:55–03:40 (good, 0.75 h)	89.7° 08:35	4.48	99%	106.0°
2033-06-14 Tue	20	—	unknown	02:55–03:40 (good, 0.75 h)	89.8° 08:30	4.46	95%	95.0°
2033-06-15 Wed	19	—	unknown	03:35–03:40 (good, 0.08 h)	89.6° 08:25	4.45	90%	83.6°
2033-06-16 Thu	18	—	unknown	01:50–03:40 (marginal, 1.83 h)	89.5° 08:20	4.44	82%	72.3°
2033-06-17 Fri	19	—	unknown	01:45–03:40 (marginal, 1.92 h)	89.6° 08:20	4.43	73%	61.2°
2033-06-18 Sat	21	—	unknown	03:30–03:40 (good, 0.17 h)	89.7° 08:15	4.43	62%	50.9°
2033-06-19 Sun	24	—	unknown	02:35–03:40 (good, 1.08 h)	89.7° 08:10	4.42	51%	42.0°
2033-06-20 Mon	30	—	unknown	02:20–03:40 (good, 1.33 h)	89.6° 08:05	4.42	39%	35.8°
2033-06-21 Tue	39	—	unknown	02:00–03:40 (good, 1.67 h)	89.5° 08:05	4.42	28%	34.1°
2033-06-22 Wed	45	—	unknown	01:55–03:40 (good, 1.75 h)	89.7° 08:00	4.43	19%	37.3°
2033-06-23 Thu	48	—	unknown	01:50–03:40 (good, 1.83 h)	89.8° 07:55	4.43	11%	44.4°
2033-06-24 Fri	50	—	unknown	01:45–03:40 (good, 1.92 h)	89.7° 07:50	4.44	5%	53.7°
2033-06-25 Sat	53	—	unknown	01:45–03:40 (good, 1.92 h)	89.5° 07:45	4.45	1%	64.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-05-27&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.