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: 10-26 (100), 10-27 (100), 10-28 (100), 10-29 (100), 10-30 (100) — by astronomy; check the weather when the night is within four days.

2029-10-17astronomy score per night — click a bar for that night2029-11-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-10-17 Wed	34	—	unknown	20:10–00:55 (marginal, 4.75 h)	71.1° 19:35	9.92	82%	44.3°
2029-10-18 Thu	32	—	unknown	20:10–00:45 (marginal, 4.58 h)	71.1° 19:35	9.96	89%	50.7°
2029-10-19 Fri	34	—	unknown	20:10–00:35 (marginal, 4.42 h)	71.1° 19:30	10.0	94%	58.4°
2029-10-20 Sat	38	—	unknown	20:05–20:15 (good, 0.17 h)	71.1° 19:25	10.05	98%	66.9°
2029-10-21 Sun	45	—	unknown	20:05–21:30 (good, 1.42 h)	71.1° 19:20	10.09	100%	75.8°
2029-10-22 Mon	55	—	unknown	20:05–22:20 (good, 2.25 h)	71.1° 19:20	10.13	100%	84.9°
2029-10-23 Tue	65	—	unknown	20:05–23:15 (good, 3.17 h)	71.1° 19:15	10.17	98%	94.1°
2029-10-24 Wed	77	—	unknown	20:00–23:50 (good, 3.83 h)	71.1° 19:10	10.21	94%	103.3°
2029-10-25 Thu	97	—	unknown	20:00–23:55 (good, 3.92 h)	71.1° 19:05	10.25	89%	112.3°
2029-10-26 Fri	100	—	unknown	20:00–00:00 (good, 4.0 h)	71.1° 19:00	10.29	83%	120.9°
2029-10-27 Sat	100	—	unknown	20:00–23:55 (good, 3.92 h)	71.1° 19:00	10.32	75%	128.8°
2029-10-28 Sun	100	—	unknown	18:55–22:55 (good, 4.0 h)	71.1° 17:55	10.36	66%	135.4°
2029-10-29 Mon	100	—	unknown	18:55–22:55 (good, 4.0 h)	71.1° 17:50	10.4	56%	139.9°
2029-10-30 Tue	100	—	unknown	18:55–22:50 (good, 3.92 h)	71.1° 17:45	10.44	45%	141.4°
2029-10-31 Wed	100	—	unknown	18:55–22:50 (good, 3.92 h)	71.1° 17:40	10.48	35%	139.1°
2029-11-01 Thu	100	—	unknown	18:50–22:45 (good, 3.92 h)	71.1° 17:40	10.51	25%	133.3°
2029-11-02 Fri	100	—	unknown	18:50–22:40 (good, 3.83 h)	71.1° 17:35	10.55	15%	124.9°
2029-11-03 Sat	99	—	unknown	18:50–22:35 (good, 3.75 h)	71.1° 17:30	10.58	8%	114.7°
2029-11-04 Sun	98	—	unknown	18:50–22:35 (good, 3.75 h)	71.1° 17:25	10.62	3%	103.4°
2029-11-05 Mon	96	—	unknown	18:50–22:30 (good, 3.67 h)	71.1° 17:20	10.65	0%	91.6°
2029-11-06 Tue	95	—	unknown	18:45–22:25 (good, 3.67 h)	71.1° 17:20	10.69	1%	79.7°
2029-11-07 Wed	94	—	unknown	18:45–22:20 (good, 3.58 h)	71.1° 17:15	10.72	4%	68.2°
2029-11-08 Thu	93	—	unknown	18:45–22:15 (good, 3.5 h)	71.1° 17:10	10.75	11%	57.7°
2029-11-09 Fri	82	—	unknown	18:45–22:15 (good, 3.5 h)	71.1° 17:05	10.79	19%	48.7°
2029-11-10 Sat	71	—	unknown	18:45–22:10 (good, 3.42 h)	71.1° 17:05	10.82	28%	42.2°
2029-11-11 Sun	58	—	unknown	18:40–21:50 (good, 3.17 h)	71.1° 17:00	10.85	39%	38.8°
2029-11-12 Mon	47	—	unknown	18:40–21:35 (good, 2.92 h)	71.1° 16:55	10.88	49%	39.2°
2029-11-13 Tue	38	—	unknown	18:40–20:05 (good, 1.42 h)	71.1° 16:50	10.91	59%	42.8°
2029-11-14 Wed	32	—	unknown	18:40–19:00 (good, 0.33 h)	71.1° 16:45	10.94	68%	48.8°
2029-11-15 Thu	29	—	unknown	18:40–22:05 (marginal, 3.42 h)	71.1° 16:45	10.97	77%	56.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-10-17&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.