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: 06-10 (100), 06-11 (100), 06-12 (100), 06-13 (100), 06-14 (100) — by astronomy; check the weather when the night is within four days.

2034-06-10astronomy score per night — click a bar for that night2034-07-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-06-10 Sat	100	—	unknown	23:05–03:40 (good, 4.58 h)	71.1° 04:05	4.53	38%	65.6°
2034-06-11 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 04:00	4.51	27%	76.3°
2034-06-12 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 04:00	4.5	17%	87.7°
2034-06-13 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:55	4.48	9%	99.3°
2034-06-14 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:50	4.47	4%	110.8°
2034-06-15 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:45	4.45	1%	121.6°
2034-06-16 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:40	4.44	0%	131.0°
2034-06-17 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:40	4.43	3%	138.0°
2034-06-18 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:35	4.43	9%	141.5°
2034-06-19 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:30	4.42	16%	140.8°
2034-06-20 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:25	4.42	24%	136.5°
2034-06-21 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:20	4.42	34%	129.8°
2034-06-22 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:20	4.43	43%	121.8°
2034-06-23 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:15	4.43	53%	113.0°
2034-06-24 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:10	4.44	63%	103.9°
2034-06-25 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:05	4.45	72%	94.7°
2034-06-26 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:05	4.46	80%	85.4°
2034-06-27 Tue	100	—	unknown	23:20–03:40 (good, 4.33 h)	71.1° 03:00	4.47	87%	76.2°
2034-06-28 Wed	66	—	unknown	00:20–03:40 (good, 3.33 h)	71.1° 02:55	4.48	92%	67.2°
2034-06-29 Thu	53	—	unknown	02:05–03:40 (good, 1.58 h)	71.1° 02:50	4.5	97%	58.5°
2034-06-30 Fri	43	—	unknown	23:10–03:45 (marginal, 4.58 h)	71.1° 02:45	4.52	99%	50.7°
2034-07-01 Sat	35	—	unknown	23:10–03:45 (marginal, 4.58 h)	71.1° 02:45	4.54	100%	44.1°
2034-07-02 Sun	32	—	unknown	23:10–03:45 (marginal, 4.58 h)	71.1° 02:40	4.56	98%	39.7°
2034-07-03 Mon	36	—	unknown	23:10–03:45 (marginal, 4.58 h)	71.1° 02:35	4.59	95%	38.4°
2034-07-04 Tue	45	—	unknown	23:10–03:45 (marginal, 4.58 h)	71.1° 02:30	4.61	89%	40.7°
2034-07-05 Wed	82	—	unknown	23:10–01:55 (good, 2.75 h)	71.1° 02:25	4.64	82%	46.2°
2034-07-06 Thu	95	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:25	4.67	73%	54.0°
2034-07-07 Fri	100	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:20	4.7	63%	63.4°
2034-07-08 Sat	100	—	unknown	23:05–03:50 (good, 4.75 h)	71.1° 02:15	4.73	52%	73.7°
2034-07-09 Sun	100	—	unknown	23:05–03:50 (good, 4.75 h)	71.1° 02:10	4.77	40%	84.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-06-10&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.