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: 06-05 (100), 06-06 (100), 06-07 (100), 06-20 (100), 06-21 (100) — by astronomy; check the weather when the night is within four days.

2033-06-05astronomy score per night — click a bar for that night2033-07-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-06-05 Sun	100	—	unknown	23:30–03:40 (good, 4.17 h)	71.1° 04:25	4.65	59%	121.9°
2033-06-06 Mon	100	—	unknown	23:30–03:40 (good, 4.17 h)	71.1° 04:20	4.63	68%	113.3°
2033-06-07 Tue	100	—	unknown	23:30–03:40 (good, 4.17 h)	71.1° 04:15	4.6	76%	104.1°
2033-06-08 Wed	99	—	unknown	23:35–03:40 (good, 4.08 h)	71.1° 04:10	4.57	84%	94.7°
2033-06-09 Thu	74	—	unknown	00:05–03:40 (good, 3.58 h)	71.1° 04:10	4.55	91%	85.0°
2033-06-10 Fri	61	—	unknown	00:55–03:40 (good, 2.75 h)	71.1° 04:05	4.53	96%	75.2°
2033-06-11 Sat	49	—	unknown	01:55–03:40 (good, 1.75 h)	71.1° 04:00	4.51	99%	65.5°
2033-06-12 Sun	40	—	unknown	23:10–03:40 (marginal, 4.5 h)	71.1° 03:55	4.49	100%	56.2°
2033-06-13 Mon	34	—	unknown	23:10–03:40 (marginal, 4.5 h)	71.1° 03:55	4.48	99%	47.8°
2033-06-14 Tue	32	—	unknown	23:10–03:40 (marginal, 4.5 h)	71.1° 03:50	4.46	95%	41.3°
2033-06-15 Wed	36	—	unknown	23:10–03:40 (marginal, 4.5 h)	71.1° 03:45	4.45	90%	37.7°
2033-06-16 Thu	67	—	unknown	23:10–23:35 (good, 0.42 h)	71.1° 03:40	4.44	82%	38.3°
2033-06-17 Fri	83	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:35	4.43	73%	42.9°
2033-06-18 Sat	93	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:35	4.43	62%	50.5°
2033-06-19 Sun	97	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:30	4.42	51%	59.9°
2033-06-20 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:25	4.42	39%	70.4°
2033-06-21 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:20	4.42	28%	81.5°
2033-06-22 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:15	4.43	19%	92.8°
2033-06-23 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:15	4.43	11%	103.9°
2033-06-24 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:10	4.44	5%	114.6°
2033-06-25 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:05	4.45	1%	124.4°
2033-06-26 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:00	4.46	0%	132.9°
2033-06-27 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:00	4.47	2%	139.1°
2033-06-28 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 02:55	4.49	5%	142.3°
2033-06-29 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 02:50	4.5	10%	141.8°
2033-06-30 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:45	4.52	17%	138.0°
2033-07-01 Fri	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:40	4.54	25%	132.0°
2033-07-02 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:40	4.57	33%	124.4°
2033-07-03 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:35	4.59	43%	116.0°
2033-07-04 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:30	4.62	52%	107.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-06-05&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.