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: 11-09 (93), 11-10 (91), 11-11 (89), 11-12 (89), 11-13 (87) — by astronomy; check the weather when the night is within four days.

2047-11-09astronomy score per night — click a bar for that night2047-12-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-11-09 Sat	93	—	unknown	18:45–22:15 (good, 3.5 h)	71.2° 17:10	10.77	59%	140.3°
2047-11-10 Sun	91	—	unknown	18:45–22:10 (good, 3.42 h)	71.2° 17:05	10.81	49%	140.1°
2047-11-11 Mon	89	—	unknown	18:45–22:05 (good, 3.33 h)	71.2° 17:00	10.84	38%	136.4°
2047-11-12 Tue	89	—	unknown	18:40–22:05 (good, 3.42 h)	71.1° 16:55	10.87	28%	129.8°
2047-11-13 Wed	87	—	unknown	18:40–22:00 (good, 3.33 h)	71.1° 16:55	10.9	18%	121.0°
2047-11-14 Thu	86	—	unknown	18:40–21:55 (good, 3.25 h)	71.2° 16:50	10.93	10%	110.7°
2047-11-15 Fri	84	—	unknown	18:40–21:50 (good, 3.17 h)	71.2° 16:45	10.96	4%	99.4°
2047-11-16 Sat	83	—	unknown	18:40–21:50 (good, 3.17 h)	71.2° 16:40	10.98	1%	87.7°
2047-11-17 Sun	80	—	unknown	18:40–21:45 (good, 3.08 h)	71.1° 16:40	11.01	0%	76.0°
2047-11-18 Mon	78	—	unknown	18:40–21:40 (good, 3.0 h)	71.2° 16:35	11.04	3%	64.8°
2047-11-19 Tue	78	—	unknown	18:35–21:35 (good, 3.0 h)	71.2° 16:30	11.07	8%	54.6°
2047-11-20 Wed	69	—	unknown	18:35–21:30 (good, 2.92 h)	71.2° 16:25	11.09	16%	46.4°
2047-11-21 Thu	59	—	unknown	18:35–21:30 (good, 2.92 h)	71.1° 16:20	11.12	25%	41.0°
2047-11-22 Fri	48	—	unknown	18:35–21:10 (good, 2.58 h)	71.1° 16:20	11.14	35%	39.3°
2047-11-23 Sat	40	—	unknown	18:35–20:55 (good, 2.33 h)	71.2° 16:15	11.17	46%	41.3°
2047-11-24 Sun	33	—	unknown	18:35–19:50 (good, 1.25 h)	71.2° 16:10	11.19	56%	46.3°
2047-11-25 Mon	28	—	unknown	18:35–18:55 (good, 0.33 h)	71.2° 16:05	11.21	65%	53.1°
2047-11-26 Tue	25	—	unknown	18:35–21:25 (marginal, 2.83 h)	71.1° 16:00	11.23	74%	61.1°
2047-11-27 Wed	25	—	unknown	18:00–21:20 (marginal, 3.33 h)	71.1° 16:00	11.25	82%	69.7°
2047-11-28 Thu	26	—	unknown	18:35–18:55 (good, 0.33 h)	71.2° 15:55	11.27	89%	78.7°
2047-11-29 Fri	29	—	unknown	18:35–19:25 (good, 0.83 h)	71.2° 15:50	11.29	94%	87.8°
2047-11-30 Sat	32	—	unknown	18:35–20:00 (good, 1.42 h)	71.2° 15:45	11.31	98%	96.9°
2047-12-01 Sun	37	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:40	11.33	100%	106.0°
2047-12-02 Mon	41	—	unknown	18:35–20:30 (good, 1.92 h)	71.2° 15:40	11.35	100%	114.7°
2047-12-03 Tue	44	—	unknown	18:35–20:30 (good, 1.92 h)	71.2° 15:35	11.36	98%	123.0°
2047-12-04 Wed	44	—	unknown	18:35–20:30 (good, 1.92 h)	71.2° 15:30	11.38	95%	130.4°
2047-12-05 Thu	48	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:25	11.39	90%	136.3°
2047-12-06 Fri	48	—	unknown	18:35–20:30 (good, 1.92 h)	71.1° 15:25	11.41	83%	140.0°
2047-12-07 Sat	46	—	unknown	18:35–20:25 (good, 1.83 h)	71.2° 15:20	11.42	74%	140.6°
2047-12-08 Sun	45	—	unknown	18:35–20:20 (good, 1.75 h)	71.2° 15:15	11.43	65%	137.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-11-09&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.