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.

2029-06-10astronomy score per night — click a bar for that night2029-07-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-06-10 Sun	100	—	unknown	23:05–03:40 (good, 4.58 h)	71.1° 04:05	4.53	2%	108.2°
2029-06-11 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 04:00	4.51	0%	117.2°
2029-06-12 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:55	4.49	1%	125.7°
2029-06-13 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:55	4.48	3%	133.1°
2029-06-14 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:50	4.46	8%	138.5°
2029-06-15 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:45	4.45	15%	140.9°
2029-06-16 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:40	4.44	24%	139.5°
2029-06-17 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:35	4.43	34%	134.6°
2029-06-18 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:35	4.43	44%	126.9°
2029-06-19 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:30	4.42	56%	117.6°
2029-06-20 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:25	4.42	67%	107.2°
2029-06-21 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:20	4.42	78%	96.2°
2029-06-22 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:15	4.43	87%	85.0°
2029-06-23 Sat	73	—	unknown	23:45–03:40 (good, 3.92 h)	71.1° 03:15	4.43	94%	73.9°
2029-06-24 Sun	57	—	unknown	00:55–03:40 (good, 2.75 h)	71.1° 03:10	4.44	98%	63.3°
2029-06-25 Mon	45	—	unknown	23:15–03:40 (marginal, 4.42 h)	71.1° 03:05	4.45	100%	53.8°
2029-06-26 Tue	37	—	unknown	23:15–03:40 (marginal, 4.42 h)	71.1° 03:00	4.46	99%	46.0°
2029-06-27 Wed	36	—	unknown	23:15–03:40 (marginal, 4.42 h)	71.1° 03:00	4.47	96%	40.8°
2029-06-28 Thu	41	—	unknown	23:10–03:40 (marginal, 4.5 h)	71.1° 02:55	4.49	91%	39.1°
2029-06-29 Fri	50	—	unknown	23:10–01:00 (good, 1.83 h)	71.1° 02:50	4.5	84%	40.9°
2029-06-30 Sat	84	—	unknown	23:10–02:45 (good, 3.58 h)	71.1° 02:45	4.52	76%	45.6°
2029-07-01 Sun	94	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:40	4.54	67%	52.2°
2029-07-02 Mon	96	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:40	4.57	58%	60.0°
2029-07-03 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:35	4.59	48%	68.5°
2029-07-04 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:30	4.62	39%	77.4°
2029-07-05 Thu	100	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:25	4.65	30%	86.5°
2029-07-06 Fri	100	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:20	4.68	21%	95.8°
2029-07-07 Sat	100	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:20	4.71	14%	105.2°
2029-07-08 Sun	100	—	unknown	23:05–03:50 (good, 4.75 h)	71.1° 02:15	4.74	8%	114.3°
2029-07-09 Mon	100	—	unknown	23:05–03:50 (good, 4.75 h)	71.1° 02:10	4.77	3%	123.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-06-10&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.