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: 10-13 (100), 10-14 (100), 10-15 (100), 10-16 (100), 10-17 (100) — by astronomy; check the weather when the night is within four days.

2047-10-13astronomy score per night — click a bar for that night2047-11-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-10-13 Sun	100	—	unknown	20:20–01:00 (good, 4.67 h)	71.2° 19:55	9.73	33%	140.3°
2047-10-14 Mon	100	—	unknown	20:15–01:00 (good, 4.75 h)	71.2° 19:50	9.77	23%	138.9°
2047-10-15 Tue	100	—	unknown	20:15–00:55 (good, 4.67 h)	71.1° 19:45	9.82	14%	134.0°
2047-10-16 Wed	100	—	unknown	20:15–00:50 (good, 4.58 h)	71.1° 19:45	9.86	7%	126.2°
2047-10-17 Thu	100	—	unknown	20:10–00:45 (good, 4.58 h)	71.2° 19:40	9.9	2%	116.4°
2047-10-18 Fri	100	—	unknown	20:10–00:40 (good, 4.5 h)	71.2° 19:35	9.95	0%	105.5°
2047-10-19 Sat	100	—	unknown	20:10–00:40 (good, 4.5 h)	71.1° 19:30	9.99	1%	93.9°
2047-10-20 Sun	100	—	unknown	20:10–00:35 (good, 4.42 h)	71.1° 19:30	10.03	5%	82.3°
2047-10-21 Mon	100	—	unknown	20:05–00:30 (good, 4.42 h)	71.2° 19:25	10.07	11%	70.9°
2047-10-22 Tue	100	—	unknown	20:05–00:25 (good, 4.33 h)	71.2° 19:20	10.11	20%	60.4°
2047-10-23 Wed	95	—	unknown	20:05–00:20 (good, 4.25 h)	71.2° 19:15	10.15	30%	51.3°
2047-10-24 Thu	82	—	unknown	20:00–00:20 (good, 4.33 h)	71.1° 19:10	10.19	40%	44.3°
2047-10-25 Fri	61	—	unknown	20:00–23:55 (good, 3.92 h)	71.1° 19:10	10.23	51%	40.3°
2047-10-26 Sat	48	—	unknown	20:00–22:35 (good, 2.58 h)	71.2° 19:05	10.27	62%	39.7°
2047-10-27 Sun	39	—	unknown	19:00–23:25 (marginal, 4.42 h)	71.2° 18:00	10.31	71%	42.6°
2047-10-28 Mon	34	—	unknown	18:55–23:15 (marginal, 4.33 h)	71.2° 17:55	10.35	80%	48.0°
2047-10-29 Tue	32	—	unknown	18:55–23:05 (marginal, 4.17 h)	71.1° 17:50	10.39	87%	55.1°
2047-10-30 Wed	33	—	unknown	18:55–23:00 (marginal, 4.08 h)	71.1° 17:50	10.42	93%	63.3°
2047-10-31 Thu	38	—	unknown	18:55–19:40 (good, 0.75 h)	71.2° 17:45	10.46	97%	72.0°
2047-11-01 Fri	45	—	unknown	18:50–20:20 (good, 1.5 h)	71.2° 17:40	10.5	99%	81.0°
2047-11-02 Sat	53	—	unknown	18:50–21:10 (good, 2.33 h)	71.2° 17:35	10.53	100%	90.1°
2047-11-03 Sun	62	—	unknown	18:50–22:00 (good, 3.17 h)	71.1° 17:35	10.57	99%	99.2°
2047-11-04 Mon	71	—	unknown	18:50–22:15 (good, 3.42 h)	71.2° 17:30	10.61	96%	108.2°
2047-11-05 Tue	80	—	unknown	18:50–22:20 (good, 3.5 h)	71.2° 17:25	10.64	91%	116.8°
2047-11-06 Wed	91	—	unknown	18:45–22:20 (good, 3.58 h)	71.2° 17:20	10.67	85%	124.8°
2047-11-07 Thu	92	—	unknown	18:45–22:15 (good, 3.5 h)	71.1° 17:15	10.71	77%	131.9°
2047-11-08 Fri	92	—	unknown	18:45–22:15 (good, 3.5 h)	71.1° 17:15	10.74	69%	137.3°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-10-13&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.