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: 07-26 (100), 08-04 (100), 08-05 (100), 08-06 (100), 08-07 (100) — by astronomy; check the weather when the night is within four days.

2034-07-26astronomy score per night — click a bar for that night2034-08-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-07-26 Wed	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:05	5.53	82%	61.1°
2034-07-27 Thu	95	—	unknown	00:25–04:20 (good, 3.92 h)	71.1° 01:00	5.58	89%	52.9°
2034-07-28 Fri	57	—	unknown	03:25–04:20 (good, 0.92 h)	71.1° 00:55	5.63	94%	45.9°
2034-07-29 Sat	43	—	unknown	22:40–04:20 (marginal, 5.67 h)	71.1° 00:55	5.69	98%	40.7°
2034-07-30 Sun	36	—	unknown	22:40–04:20 (marginal, 5.67 h)	71.1° 00:50	5.74	100%	38.4°
2034-07-31 Mon	39	—	unknown	22:35–04:25 (marginal, 5.83 h)	71.1° 00:45	5.8	99%	39.8°
2034-08-01 Tue	47	—	unknown	22:35–04:25 (marginal, 5.83 h)	71.1° 00:40	5.85	97%	44.6°
2034-08-02 Wed	62	—	unknown	22:35–00:00 (good, 1.42 h)	71.1° 00:35	5.91	92%	52.1°
2034-08-03 Thu	75	—	unknown	22:30–02:30 (good, 4.0 h)	71.1° 00:35	5.96	85%	61.2°
2034-08-04 Fri	100	—	unknown	22:30–03:50 (good, 5.33 h)	71.1° 00:30	6.02	76%	71.5°
2034-08-05 Sat	100	—	unknown	22:30–04:30 (good, 6.0 h)	71.1° 00:25	6.07	65%	82.3°
2034-08-06 Sun	100	—	unknown	22:25–04:35 (good, 6.17 h)	71.1° 00:20	6.13	54%	93.3°
2034-08-07 Mon	100	—	unknown	22:25–04:35 (good, 6.17 h)	71.1° 00:15	6.19	42%	104.4°
2034-08-08 Tue	100	—	unknown	22:20–04:35 (good, 6.25 h)	71.1° 00:15	6.24	31%	115.0°
2034-08-09 Wed	100	—	unknown	22:20–04:40 (good, 6.33 h)	71.1° 00:10	6.3	21%	124.9°
2034-08-10 Thu	100	—	unknown	22:20–04:40 (good, 6.33 h)	71.1° 00:05	6.36	13%	133.3°
2034-08-11 Fri	100	—	unknown	22:15–04:40 (good, 6.42 h)	71.1° 00:00	6.42	6%	139.2°
2034-08-12 Sat	100	—	unknown	22:15–04:45 (good, 6.5 h)	71.1° 00:00	6.47	2%	141.6°
2034-08-13 Sun	100	—	unknown	22:15–04:45 (good, 6.5 h)	71.1° 23:55	6.53	0%	139.9°
2034-08-14 Mon	100	—	unknown	22:10–04:45 (good, 6.58 h)	71.1° 23:50	6.59	1%	134.8°
2034-08-15 Tue	100	—	unknown	22:10–04:50 (good, 6.67 h)	71.1° 23:45	6.65	4%	127.5°
2034-08-16 Wed	100	—	unknown	22:05–04:50 (good, 6.75 h)	71.1° 23:40	6.7	8%	119.0°
2034-08-17 Thu	100	—	unknown	22:05–04:45 (good, 6.67 h)	71.1° 23:40	6.76	15%	109.9°
2034-08-18 Fri	100	—	unknown	22:05–04:40 (good, 6.58 h)	71.1° 23:35	6.82	22%	100.5°
2034-08-19 Sat	100	—	unknown	22:00–04:35 (good, 6.58 h)	71.1° 23:30	6.88	31%	91.2°
2034-08-20 Sun	100	—	unknown	22:00–04:35 (good, 6.58 h)	71.1° 23:25	6.93	40%	81.8°
2034-08-21 Mon	100	—	unknown	21:55–04:30 (good, 6.58 h)	71.1° 23:20	6.99	49%	72.7°
2034-08-22 Tue	100	—	unknown	21:55–04:25 (good, 6.5 h)	71.1° 23:20	7.05	58%	63.9°
2034-08-23 Wed	98	—	unknown	21:55–04:20 (good, 6.42 h)	71.1° 23:15	7.11	68%	55.6°
2034-08-24 Thu	91	—	unknown	21:50–04:15 (good, 6.42 h)	71.1° 23:10	7.16	77%	48.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-07-26&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.