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: 07-17 (100), 07-18 (100), 07-19 (100), 07-20 (100), 07-21 (100) — by astronomy; check the weather when the night is within four days.

2033-07-10astronomy score per night — click a bar for that night2033-08-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2033-07-17 Sun	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:40	5.1	64%	68.2°
2033-07-18 Mon	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:35	5.15	53%	79.2°
2033-07-19 Tue	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:30	5.19	41%	90.4°
2033-07-20 Wed	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:25	5.24	31%	101.4°
2033-07-21 Thu	100	—	unknown	22:50–04:10 (good, 5.33 h)	71.1° 01:25	5.29	21%	112.0°
2033-07-22 Fri	100	—	unknown	22:50–04:10 (good, 5.33 h)	71.1° 01:20	5.34	13%	121.9°
2033-07-23 Sat	100	—	unknown	22:50–04:10 (good, 5.33 h)	71.1° 01:15	5.39	6%	130.6°
2033-07-24 Sun	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:10	5.44	2%	137.5°
2033-07-25 Mon	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:10	5.49	0%	141.6°
2033-07-26 Tue	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:05	5.54	0%	142.3°
2033-07-27 Wed	100	—	unknown	22:40–04:20 (good, 5.67 h)	71.1° 01:00	5.59	3%	139.5°
2033-07-28 Thu	100	—	unknown	22:40–04:20 (good, 5.67 h)	71.1° 00:55	5.65	7%	134.0°
2033-07-29 Fri	100	—	unknown	22:40–04:20 (good, 5.67 h)	71.1° 00:50	5.7	12%	126.8°
2033-07-30 Sat	100	—	unknown	22:40–04:25 (good, 5.75 h)	71.1° 00:50	5.76	19%	118.6°
2033-07-31 Sun	100	—	unknown	22:35–04:25 (good, 5.83 h)	71.1° 00:45	5.81	27%	109.8°
2033-08-01 Mon	100	—	unknown	22:35–04:25 (good, 5.83 h)	71.1° 00:40	5.86	36%	100.6°
2033-08-02 Tue	100	—	unknown	22:30–04:30 (good, 6.0 h)	71.1° 00:35	5.92	45%	91.2°
2033-08-03 Wed	100	—	unknown	22:30–04:30 (good, 6.0 h)	71.1° 00:30	5.98	55%	81.7°
2033-08-04 Thu	100	—	unknown	22:30–04:30 (good, 6.0 h)	71.1° 00:30	6.03	64%	72.1°
2033-08-05 Fri	100	—	unknown	22:25–04:30 (good, 6.08 h)	71.1° 00:25	6.09	74%	62.7°
2033-08-06 Sat	96	—	unknown	22:25–04:35 (good, 6.17 h)	71.1° 00:20	6.14	82%	53.7°
2033-08-07 Sun	89	—	unknown	01:45–04:35 (good, 2.83 h)	71.1° 00:15	6.2	90%	45.8°
2033-08-08 Mon	47	—	unknown	22:20–04:35 (marginal, 6.25 h)	71.1° 00:10	6.26	95%	39.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-07-10&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.