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: 07-19 (100), 07-20 (100), 07-21 (100), 07-22 (100), 07-23 (100) — by astronomy; check the weather when the night is within four days.

2028-07-01astronomy score per night — click a bar for that night2028-07-30

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2028-07-10 Mon	30	—	unknown	00:15–03:55 (marginal, 3.67 h)	89.5° 06:45	4.82	84%	56.7°
2028-07-11 Tue	30	—	unknown	00:10–03:55 (marginal, 3.75 h)	89.6° 06:45	4.86	77%	47.2°
2028-07-12 Wed	33	—	unknown	00:05–03:55 (marginal, 3.83 h)	89.7° 06:40	4.9	68%	38.7°
2028-07-13 Thu	38	—	unknown	03:05–04:00 (good, 0.92 h)	89.7° 06:35	4.94	59%	32.0°
2028-07-14 Fri	49	—	unknown	00:55–04:00 (good, 3.08 h)	89.6° 06:30	4.98	49%	28.3°
2028-07-15 Sat	61	—	unknown	00:25–04:00 (good, 3.58 h)	89.5° 06:25	5.02	40%	29.2°
2028-07-16 Sun	75	—	unknown	00:20–04:00 (good, 3.67 h)	89.6° 06:25	5.06	30%	34.4°
2028-07-17 Mon	88	—	unknown	00:15–04:05 (good, 3.83 h)	89.7° 06:20	5.11	21%	42.8°
2028-07-18 Tue	95	—	unknown	00:10–04:05 (good, 3.92 h)	89.7° 06:15	5.15	13%	53.0°
2028-07-19 Wed	100	—	unknown	00:10–04:05 (good, 3.92 h)	89.6° 06:10	5.2	6%	64.5°
2028-07-20 Thu	100	—	unknown	00:05–04:10 (good, 4.08 h)	89.5° 06:10	5.25	2%	76.8°
2028-07-21 Fri	100	—	unknown	00:00–04:10 (good, 4.17 h)	89.6° 06:05	5.3	0%	89.5°
2028-07-22 Sat	100	—	unknown	23:55–04:10 (good, 4.25 h)	89.7° 06:00	5.35	1%	102.5°
2028-07-23 Sun	100	—	unknown	23:50–04:10 (good, 4.33 h)	89.7° 05:55	5.4	5%	115.4°
2028-07-24 Mon	100	—	unknown	23:50–04:15 (good, 4.42 h)	89.5° 05:50	5.45	11%	127.8°
2028-07-25 Tue	100	—	unknown	23:45–04:15 (good, 4.5 h)	89.5° 05:50	5.5	20%	138.9°
2028-07-26 Wed	100	—	unknown	23:40–04:15 (good, 4.58 h)	89.7° 05:45	5.55	30%	147.6°
2028-07-27 Thu	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.7° 05:40	5.6	41%	151.8°
2028-07-28 Fri	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.6° 05:35	5.66	52%	149.9°
2028-07-29 Sat	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.5° 05:30	5.71	63%	143.2°
2028-07-30 Sun	100	—	unknown	23:30–04:25 (good, 4.92 h)	89.6° 05:30	5.77	73%	134.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-07-01&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.