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: 06-16 (100), 06-17 (100), 06-18 (100), 06-19 (100), 06-20 (100) — by astronomy; check the weather when the night is within four days.

2047-06-09astronomy score per night — click a bar for that night2047-07-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-06-09 Sun	38	—	unknown	23:05–03:40 (marginal, 4.58 h)	71.2° 04:10	4.56	95%	47.9°
2047-06-10 Mon	50	—	unknown	23:05–23:20 (good, 0.25 h)	71.1° 04:05	4.54	90%	42.3°
2047-06-11 Tue	67	—	unknown	23:10–23:55 (good, 0.75 h)	71.1° 04:05	4.52	82%	40.0°
2047-06-12 Wed	79	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 04:00	4.5	73%	41.3°
2047-06-13 Thu	89	—	unknown	23:10–03:40 (good, 4.5 h)	71.2° 03:55	4.48	64%	45.7°
2047-06-14 Fri	94	—	unknown	23:10–03:40 (good, 4.5 h)	71.2° 03:50	4.47	54%	52.0°
2047-06-15 Sat	97	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:45	4.45	44%	59.6°
2047-06-16 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:45	4.44	35%	67.9°
2047-06-17 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.2° 03:40	4.44	26%	76.6°
2047-06-18 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.2° 03:35	4.43	18%	85.6°
2047-06-19 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.2° 03:30	4.42	12%	94.7°
2047-06-20 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:25	4.42	6%	103.8°
2047-06-21 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:25	4.42	2%	112.7°
2047-06-22 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.2° 03:20	4.42	0%	121.3°
2047-06-23 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.2° 03:15	4.43	0%	129.0°
2047-06-24 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:10	4.44	2%	135.3°
2047-06-25 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:10	4.44	6%	139.2°
2047-06-26 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:05	4.45	13%	139.9°
2047-06-27 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.2° 03:00	4.47	21%	137.0°
2047-06-28 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.2° 02:55	4.48	30%	131.1°
2047-06-29 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 02:50	4.5	41%	122.9°
2047-06-30 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:50	4.52	52%	113.4°
2047-07-01 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.2° 02:45	4.54	64%	102.9°
2047-07-02 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.2° 02:40	4.56	74%	92.0°
2047-07-03 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.2° 02:35	4.58	84%	80.9°
2047-07-04 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:30	4.61	92%	70.1°
2047-07-05 Fri	61	—	unknown	00:25–03:45 (good, 3.33 h)	71.1° 02:30	4.64	97%	59.9°
2047-07-06 Sat	47	—	unknown	23:10–04:40 (marginal, 5.5 h)	71.2° 02:25	4.67	100%	51.0°
2047-07-07 Sun	38	—	unknown	23:10–03:50 (marginal, 4.67 h)	71.2° 02:20	4.7	100%	44.2°
2047-07-08 Mon	37	—	unknown	23:05–03:50 (marginal, 4.75 h)	71.1° 02:15	4.73	97%	40.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-06-09&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.