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

2046-07-04astronomy score per night — click a bar for that night2046-08-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-07-04 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:30	4.61	1%	135.0°
2046-07-05 Thu	100	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:25	4.64	4%	138.2°
2046-07-06 Fri	100	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:25	4.67	11%	137.5°
2046-07-07 Sat	100	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:20	4.7	19%	133.1°
2046-07-08 Sun	100	—	unknown	23:05–03:50 (good, 4.75 h)	71.1° 02:15	4.74	29%	125.9°
2046-07-09 Mon	100	—	unknown	23:05–03:50 (good, 4.75 h)	71.1° 02:10	4.77	40%	117.0°
2046-07-10 Tue	100	—	unknown	23:05–03:55 (good, 4.83 h)	71.1° 02:10	4.81	51%	107.1°
2046-07-11 Wed	100	—	unknown	23:05–03:55 (good, 4.83 h)	71.1° 02:05	4.84	62%	96.8°
2046-07-12 Thu	100	—	unknown	23:05–03:55 (good, 4.83 h)	71.1° 02:00	4.88	73%	86.5°
2046-07-13 Fri	100	—	unknown	23:00–03:55 (good, 4.92 h)	71.1° 01:55	4.92	82%	76.4°
2046-07-14 Sat	100	—	unknown	23:00–04:00 (good, 5.0 h)	71.1° 01:50	4.96	90%	66.8°
2046-07-15 Sun	98	—	unknown	23:40–04:00 (good, 4.33 h)	71.1° 01:50	5.01	95%	58.0°
2046-07-16 Mon	53	—	unknown	03:10–04:00 (good, 0.83 h)	71.1° 01:45	5.05	99%	50.6°
2046-07-17 Tue	43	—	unknown	22:55–04:05 (marginal, 5.17 h)	71.1° 01:40	5.09	100%	45.0°
2046-07-18 Wed	40	—	unknown	22:55–04:05 (marginal, 5.17 h)	71.1° 01:35	5.14	99%	42.0°
2046-07-19 Thu	43	—	unknown	22:55–04:05 (marginal, 5.17 h)	71.1° 01:30	5.19	96%	41.9°
2046-07-20 Fri	50	—	unknown	22:55–23:25 (good, 0.5 h)	71.1° 01:30	5.23	92%	44.6°
2046-07-21 Sat	62	—	unknown	22:50–00:50 (good, 2.0 h)	71.1° 01:25	5.28	86%	49.6°
2046-07-22 Sun	73	—	unknown	22:50–02:55 (good, 4.08 h)	71.1° 01:20	5.33	79%	56.1°
2046-07-23 Mon	98	—	unknown	22:50–04:10 (good, 5.33 h)	71.1° 01:15	5.38	70%	63.7°
2046-07-24 Tue	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:15	5.43	62%	71.9°
2046-07-25 Wed	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:10	5.48	52%	80.7°
2046-07-26 Thu	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:05	5.53	42%	89.7°
2046-07-27 Fri	100	—	unknown	22:45–04:20 (good, 5.58 h)	71.1° 01:00	5.59	33%	98.9°
2046-07-28 Sat	100	—	unknown	22:40–04:20 (good, 5.67 h)	71.1° 00:55	5.64	23%	108.2°
2046-07-29 Sun	100	—	unknown	22:40–04:20 (good, 5.67 h)	71.1° 00:55	5.69	15%	117.3°
2046-07-30 Mon	100	—	unknown	22:40–04:25 (good, 5.75 h)	71.1° 00:50	5.75	8%	125.7°
2046-07-31 Tue	100	—	unknown	22:35–04:25 (good, 5.83 h)	71.1° 00:45	5.8	3%	132.8°
2046-08-01 Wed	100	—	unknown	22:35–04:25 (good, 5.83 h)	71.1° 00:40	5.86	0%	137.4°
2046-08-02 Thu	100	—	unknown	22:35–04:25 (good, 5.83 h)	71.1° 00:35	5.91	0%	138.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-07-04&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.