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: 07-01 (64), 06-30 (63), 06-29 (59), 06-28 (58), 06-27 (55) — by astronomy; check the weather when the night is within four days.

2030-06-02astronomy score per night — click a bar for that night2030-07-01

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-06-02 Sun	21	—	unknown	03:15–03:45 (good, 0.5 h)	89.6° 09:20	4.76	2%	68.2°
2030-06-03 Mon	22	—	unknown	03:10–03:45 (good, 0.58 h)	89.7° 09:15	4.73	6%	78.6°
2030-06-04 Tue	23	—	unknown	03:05–03:45 (good, 0.67 h)	89.7° 09:10	4.69	12%	89.1°
2030-06-05 Wed	24	—	unknown	03:05–03:40 (good, 0.58 h)	89.6° 09:05	4.66	19%	99.8°
2030-06-06 Thu	25	—	unknown	03:00–03:40 (good, 0.67 h)	89.5° 09:05	4.63	28%	110.6°
2030-06-07 Fri	26	—	unknown	02:55–03:40 (good, 0.75 h)	89.7° 09:00	4.61	37%	121.3°
2030-06-08 Sat	27	—	unknown	02:50–03:40 (good, 0.83 h)	89.7° 08:55	4.58	48%	131.7°
2030-06-09 Sun	28	—	unknown	02:45–03:40 (good, 0.92 h)	89.7° 08:50	4.56	58%	141.1°
2030-06-10 Mon	30	—	unknown	02:45–03:40 (good, 0.92 h)	89.5° 08:45	4.53	69%	148.2°
2030-06-11 Tue	31	—	unknown	02:40–03:40 (good, 1.0 h)	89.6° 08:45	4.51	79%	150.7°
2030-06-12 Wed	31	—	unknown	02:45–03:40 (good, 0.92 h)	89.7° 08:40	4.5	88%	146.9°
2030-06-13 Thu	29	—	unknown	02:40–03:40 (good, 1.0 h)	89.7° 08:35	4.48	95%	138.4°
2030-06-14 Fri	29	—	unknown	02:40–03:40 (good, 1.0 h)	89.7° 08:30	4.46	99%	127.2°
2030-06-15 Sat	28	—	unknown	02:40–03:40 (good, 1.0 h)	89.5° 08:25	4.45	100%	114.7°
2030-06-16 Sun	24	—	unknown	02:45–03:40 (good, 0.92 h)	89.6° 08:25	4.44	98%	101.9°
2030-06-17 Mon	21	—	unknown	03:05–03:40 (good, 0.58 h)	89.7° 08:20	4.43	93%	89.1°
2030-06-18 Tue	19	—	unknown	01:40–03:40 (marginal, 2.0 h)	89.7° 08:15	4.43	86%	76.7°
2030-06-19 Wed	19	—	unknown	01:40–03:40 (marginal, 2.0 h)	89.6° 08:10	4.42	78%	64.8°
2030-06-20 Thu	20	—	unknown	01:30–03:40 (marginal, 2.17 h)	89.5° 08:10	4.42	68%	53.8°
2030-06-21 Fri	23	—	unknown	03:25–03:40 (good, 0.25 h)	89.6° 08:05	4.42	58%	44.0°
2030-06-22 Sat	26	—	unknown	02:25–03:40 (good, 1.25 h)	89.7° 08:00	4.42	48%	36.0°
2030-06-23 Sun	31	—	unknown	02:10–03:40 (good, 1.5 h)	89.7° 07:55	4.43	38%	30.7°
2030-06-24 Mon	38	—	unknown	01:50–03:40 (good, 1.83 h)	89.6° 07:50	4.44	29%	29.4°
2030-06-25 Tue	45	—	unknown	01:45–03:40 (good, 1.92 h)	89.5° 07:50	4.44	21%	32.4°
2030-06-26 Wed	51	—	unknown	01:40–03:40 (good, 2.0 h)	89.7° 07:45	4.46	14%	38.5°
2030-06-27 Thu	55	—	unknown	01:35–03:40 (good, 2.08 h)	89.7° 07:40	4.47	8%	46.6°
2030-06-28 Fri	58	—	unknown	01:35–03:40 (good, 2.08 h)	89.7° 07:35	4.48	4%	55.8°
2030-06-29 Sat	59	—	unknown	01:30–03:40 (good, 2.17 h)	89.5° 07:30	4.5	1%	65.7°
2030-06-30 Sun	63	—	unknown	01:25–03:45 (good, 2.33 h)	89.6° 07:30	4.52	0%	76.0°
2030-07-01 Mon	64	—	unknown	01:20–03:45 (good, 2.42 h)	89.7° 07:25	4.54	1%	86.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-06-02&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.