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: 06-20 (100), 06-21 (100), 06-22 (100), 06-23 (100), 06-24 (100) — by astronomy; check the weather when the night is within four days.

2033-06-17astronomy score per night — click a bar for that night2033-07-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2033-07-05 Tue	100	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:25	4.65	62%	97.7°
2033-07-06 Wed	100	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:20	4.68	71%	88.2°
2033-07-07 Thu	100	—	unknown	23:05–03:50 (good, 4.75 h)	71.1° 02:20	4.71	79%	78.5°
2033-07-08 Fri	100	—	unknown	23:05–03:50 (good, 4.75 h)	71.1° 02:15	4.74	87%	68.8°
2033-07-09 Sat	66	—	unknown	00:20–03:50 (good, 3.5 h)	71.1° 02:10	4.78	93%	59.3°
2033-07-10 Sun	51	—	unknown	03:20–03:55 (good, 0.58 h)	71.1° 02:05	4.81	97%	50.5°
2033-07-11 Mon	39	—	unknown	23:05–03:55 (marginal, 4.83 h)	71.1° 02:05	4.85	100%	43.2°
2033-07-12 Tue	32	—	unknown	23:05–03:55 (marginal, 4.83 h)	71.1° 02:00	4.89	99%	38.5°
2033-07-13 Wed	35	—	unknown	23:00–03:55 (marginal, 4.92 h)	71.1° 01:55	4.93	97%	37.8°
2033-07-14 Thu	45	—	unknown	23:00–04:00 (marginal, 5.0 h)	71.1° 01:50	4.97	92%	41.4°
2033-07-15 Fri	61	—	unknown	23:00–01:20 (good, 2.33 h)	71.1° 01:45	5.01	84%	48.6°
2033-07-16 Sat	96	—	unknown	23:00–04:00 (good, 5.0 h)	71.1° 01:45	5.06	75%	57.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-06-17&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.