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 HD 189733: 12-04 (48), 12-05 (48), 12-06 (47), 12-07 (46), 12-08 (44) — by astronomy; check the weather when the night is within four days.

2028-11-25astronomy score per night — click a bar for that night2028-12-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-11-25 Sat	27	—	unknown	18:35–18:45 (good, 0.17 h)	71.1° 16:05	11.22	68%	55.4°
2028-11-26 Sun	25	—	unknown	18:35–21:20 (marginal, 2.75 h)	71.1° 16:00	11.25	76%	63.2°
2028-11-27 Mon	25	—	unknown	18:00–21:15 (marginal, 3.25 h)	71.1° 15:55	11.27	84%	71.8°
2028-11-28 Tue	26	—	unknown	18:35–19:00 (good, 0.42 h)	71.1° 15:50	11.29	90%	80.9°
2028-11-29 Wed	29	—	unknown	18:35–19:30 (good, 0.92 h)	71.1° 15:45	11.3	95%	90.3°
2028-11-30 Thu	33	—	unknown	18:35–20:10 (good, 1.58 h)	71.1° 15:45	11.32	98%	99.8°
2028-12-01 Fri	38	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:40	11.34	100%	109.4°
2028-12-02 Sat	43	—	unknown	18:35–20:30 (good, 1.92 h)	71.1° 15:35	11.36	99%	118.6°
2028-12-03 Sun	43	—	unknown	18:35–20:30 (good, 1.92 h)	71.1° 15:30	11.37	96%	127.1°
2028-12-04 Mon	48	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:25	11.39	91%	134.2°
2028-12-05 Tue	48	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:25	11.4	84%	138.9°
2028-12-06 Wed	47	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:20	11.41	75%	140.1°
2028-12-07 Thu	46	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 15:15	11.43	65%	137.4°
2028-12-08 Fri	44	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 15:10	11.44	54%	131.4°
2028-12-09 Sat	42	—	unknown	18:35–20:15 (good, 1.67 h)	71.1° 15:10	11.45	42%	123.1°
2028-12-10 Sun	40	—	unknown	18:35–20:10 (good, 1.58 h)	71.1° 15:05	11.46	31%	113.3°
2028-12-11 Mon	39	—	unknown	18:35–20:05 (good, 1.5 h)	71.1° 15:00	11.47	21%	102.8°
2028-12-12 Tue	38	—	unknown	18:35–20:00 (good, 1.42 h)	71.1° 14:55	11.48	12%	92.0°
2028-12-13 Wed	36	—	unknown	18:35–20:00 (good, 1.42 h)	71.1° 14:50	11.48	6%	81.1°
2028-12-14 Thu	34	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 14:50	11.49	2%	70.6°
2028-12-15 Fri	34	—	unknown	18:35–19:50 (good, 1.25 h)	71.1° 14:45	11.49	0%	60.7°
2028-12-16 Sat	32	—	unknown	18:35–19:45 (good, 1.17 h)	71.1° 14:40	11.5	1%	52.1°
2028-12-17 Sun	30	—	unknown	18:35–19:45 (good, 1.17 h)	71.1° 14:35	11.5	4%	45.3°
2028-12-18 Mon	27	—	unknown	18:35–19:40 (good, 1.08 h)	71.1° 14:30	11.51	9%	41.0°
2028-12-19 Tue	24	—	unknown	18:35–19:30 (good, 0.92 h)	71.1° 14:30	11.51	15%	39.8°
2028-12-20 Wed	20	—	unknown	18:35–19:20 (good, 0.75 h)	71.1° 14:25	11.51	23%	41.9°
2028-12-21 Thu	17	—	unknown	18:35–19:10 (good, 0.58 h)	71.1° 14:20	11.51	32%	46.5°
2028-12-22 Fri	14	—	unknown	18:35–19:00 (good, 0.42 h)	71.1° 14:15	11.51	41%	52.9°
2028-12-23 Sat	11	—	unknown	18:40–18:45 (good, 0.08 h)	71.1° 14:15	11.5	50%	60.5°
2028-12-24 Sun	10	—	unknown	18:40–19:40 (marginal, 1.0 h)	71.1° 14:10	11.5	60%	68.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-11-25&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.