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 (65), 07-03 (65), 07-01 (64), 06-30 (63), 06-29 (61) — by astronomy; check the weather when the night is within four days.

2028-06-10astronomy score per night — click a bar for that night2028-07-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-06-10 Sat	17	—	unknown	03:20–03:40 (good, 0.33 h)	89.7° 08:45	4.52	86%	84.6°
2028-06-11 Sun	16	—	unknown	02:05–03:40 (marginal, 1.58 h)	89.7° 08:40	4.5	79%	73.9°
2028-06-12 Mon	17	—	unknown	02:00–03:40 (marginal, 1.67 h)	89.5° 08:35	4.49	71%	63.6°
2028-06-13 Tue	18	—	unknown	01:55–04:30 (marginal, 2.58 h)	89.6° 08:35	4.47	62%	53.7°
2028-06-14 Wed	20	—	unknown	02:55–03:40 (good, 0.75 h)	89.7° 08:30	4.46	52%	44.4°
2028-06-15 Thu	23	—	unknown	02:45–03:40 (good, 0.92 h)	89.7° 08:25	4.45	43%	36.4°
2028-06-16 Fri	27	—	unknown	02:35–03:40 (good, 1.08 h)	89.6° 08:20	4.44	34%	30.4°
2028-06-17 Sat	32	—	unknown	02:25–03:40 (good, 1.25 h)	89.5° 08:15	4.43	25%	28.1°
2028-06-18 Sun	37	—	unknown	02:10–03:40 (good, 1.5 h)	89.6° 08:15	4.43	16%	30.7°
2028-06-19 Mon	42	—	unknown	02:05–03:40 (good, 1.58 h)	89.7° 08:10	4.42	10%	37.4°
2028-06-20 Tue	44	—	unknown	02:00–03:40 (good, 1.67 h)	89.7° 08:05	4.42	4%	46.7°
2028-06-21 Wed	46	—	unknown	02:00–03:40 (good, 1.67 h)	89.6° 08:00	4.42	1%	57.5°
2028-06-22 Thu	48	—	unknown	01:55–03:40 (good, 1.75 h)	89.5° 08:00	4.43	0%	69.4°
2028-06-23 Fri	50	—	unknown	01:50–03:40 (good, 1.83 h)	89.7° 07:55	4.43	2%	81.8°
2028-06-24 Sat	51	—	unknown	01:45–03:40 (good, 1.92 h)	89.7° 07:50	4.44	6%	94.4°
2028-06-25 Sun	53	—	unknown	01:40–03:40 (good, 2.0 h)	89.7° 07:45	4.45	13%	107.1°
2028-06-26 Mon	55	—	unknown	01:40–03:40 (good, 2.0 h)	89.5° 07:40	4.46	22%	119.5°
2028-06-27 Tue	57	—	unknown	01:35–03:40 (good, 2.08 h)	89.6° 07:40	4.47	32%	131.2°
2028-06-28 Wed	59	—	unknown	01:30–03:40 (good, 2.17 h)	89.7° 07:35	4.49	43%	141.6°
2028-06-29 Thu	61	—	unknown	01:25–03:45 (good, 2.33 h)	89.7° 07:30	4.51	55%	149.2°
2028-06-30 Fri	63	—	unknown	01:25–03:45 (good, 2.33 h)	89.6° 07:25	4.53	66%	151.9°
2028-07-01 Sat	64	—	unknown	01:25–03:45 (good, 2.33 h)	89.5° 07:20	4.55	76%	148.7°
2028-07-02 Sun	65	—	unknown	01:25–03:45 (good, 2.33 h)	89.6° 07:20	4.57	85%	141.3°
2028-07-03 Mon	65	—	unknown	01:20–03:45 (good, 2.42 h)	89.7° 07:15	4.6	92%	131.6°
2028-07-04 Tue	60	—	unknown	01:20–03:45 (good, 2.42 h)	89.7° 07:10	4.62	96%	121.0°
2028-07-05 Wed	55	—	unknown	01:20–03:50 (good, 2.5 h)	89.6° 07:05	4.65	99%	110.1°
2028-07-06 Thu	48	—	unknown	01:25–03:50 (good, 2.42 h)	89.5° 07:05	4.68	100%	99.0°
2028-07-07 Fri	42	—	unknown	01:55–03:50 (good, 1.92 h)	89.7° 07:00	4.71	99%	88.0°
2028-07-08 Sat	36	—	unknown	03:00–03:50 (good, 0.83 h)	89.7° 06:55	4.75	95%	77.3°
2028-07-09 Sun	32	—	unknown	00:20–03:55 (marginal, 3.58 h)	89.7° 06:50	4.78	90%	66.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-06-10&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.