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: 05-31 (100), 06-01 (100), 06-02 (100), 06-03 (100), 06-16 (100) — by astronomy; check the weather when the night is within four days.

2036-05-31astronomy score per night — click a bar for that night2036-06-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-05-31 Sat	100	—	unknown	23:45–03:45 (good, 4.0 h)	71.1° 04:45	4.81	44%	131.0°
2036-06-01 Sun	100	—	unknown	23:45–03:45 (good, 4.0 h)	71.1° 04:40	4.78	55%	123.2°
2036-06-02 Mon	100	—	unknown	23:45–03:45 (good, 4.0 h)	71.1° 04:35	4.74	66%	114.1°
2036-06-03 Tue	100	—	unknown	23:45–03:45 (good, 4.0 h)	71.1° 04:30	4.71	76%	104.4°
2036-06-04 Wed	80	—	unknown	23:50–03:40 (good, 3.83 h)	71.1° 04:25	4.68	84%	94.6°
2036-06-05 Thu	68	—	unknown	00:25–03:40 (good, 3.25 h)	71.1° 04:25	4.65	91%	84.7°
2036-06-06 Fri	57	—	unknown	01:20–03:40 (good, 2.33 h)	71.1° 04:20	4.62	96%	75.2°
2036-06-07 Sat	47	—	unknown	02:10–03:40 (good, 1.5 h)	71.1° 04:15	4.59	99%	66.1°
2036-06-08 Sun	40	—	unknown	23:05–03:40 (marginal, 4.58 h)	71.1° 04:10	4.57	100%	57.9°
2036-06-09 Mon	35	—	unknown	23:05–03:40 (marginal, 4.58 h)	71.1° 04:05	4.54	99%	50.7°
2036-06-10 Tue	34	—	unknown	23:05–03:40 (marginal, 4.58 h)	71.1° 04:05	4.52	96%	45.2°
2036-06-11 Wed	38	—	unknown	23:10–03:40 (marginal, 4.5 h)	71.1° 04:00	4.5	91%	41.9°
2036-06-12 Thu	66	—	unknown	23:10–23:45 (good, 0.58 h)	71.1° 03:55	4.49	85%	41.2°
2036-06-13 Fri	79	—	unknown	23:10–03:30 (good, 4.33 h)	71.1° 03:50	4.47	78%	43.3°
2036-06-14 Sat	92	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:50	4.46	70%	47.7°
2036-06-15 Sun	96	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:45	4.45	61%	54.0°
2036-06-16 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:40	4.44	51%	61.6°
2036-06-17 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:35	4.43	41%	70.2°
2036-06-18 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:30	4.43	31%	79.5°
2036-06-19 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:30	4.42	22%	89.3°
2036-06-20 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:25	4.42	14%	99.5°
2036-06-21 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:20	4.42	7%	109.8°
2036-06-22 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:15	4.43	2%	119.7°
2036-06-23 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:10	4.43	0%	128.6°
2036-06-24 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:10	4.44	1%	135.3°
2036-06-25 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:05	4.45	5%	138.7°
2036-06-26 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:00	4.46	11%	137.7°
2036-06-27 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 02:55	4.48	20%	132.8°
2036-06-28 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 02:55	4.49	30%	125.2°
2036-06-29 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:50	4.51	41%	116.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-05-31&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.