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: 07-09 (100), 07-10 (100), 07-11 (100), 07-12 (100), 07-13 (100) — by astronomy; check the weather when the night is within four days.

2034-07-09astronomy score per night — click a bar for that night2034-08-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-07-09 Sun	100	—	unknown	23:05–03:50 (good, 4.75 h)	71.1° 02:10	4.77	40%	84.6°
2034-07-10 Mon	100	—	unknown	23:05–03:55 (good, 4.83 h)	71.1° 02:05	4.8	29%	95.8°
2034-07-11 Tue	100	—	unknown	23:05–03:55 (good, 4.83 h)	71.1° 02:05	4.84	19%	107.0°
2034-07-12 Wed	100	—	unknown	23:05–03:55 (good, 4.83 h)	71.1° 02:00	4.88	11%	117.8°
2034-07-13 Thu	100	—	unknown	23:00–03:55 (good, 4.92 h)	71.1° 01:55	4.92	5%	127.6°
2034-07-14 Fri	100	—	unknown	23:00–04:00 (good, 5.0 h)	71.1° 01:50	4.96	1%	135.5°
2034-07-15 Sat	100	—	unknown	23:00–04:00 (good, 5.0 h)	71.1° 01:50	5.0	0%	140.5°
2034-07-16 Sun	100	—	unknown	23:00–04:00 (good, 5.0 h)	71.1° 01:45	5.04	2%	141.5°
2034-07-17 Mon	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:40	5.09	6%	138.4°
2034-07-18 Tue	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:35	5.13	12%	132.3°
2034-07-19 Wed	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:30	5.18	19%	124.6°
2034-07-20 Thu	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:30	5.23	28%	115.9°
2034-07-21 Fri	100	—	unknown	22:50–04:10 (good, 5.33 h)	71.1° 01:25	5.28	37%	106.7°
2034-07-22 Sat	100	—	unknown	22:50–04:10 (good, 5.33 h)	71.1° 01:20	5.33	47%	97.4°
2034-07-23 Sun	100	—	unknown	22:50–04:10 (good, 5.33 h)	71.1° 01:15	5.38	56%	88.1°
2034-07-24 Mon	100	—	unknown	22:50–04:15 (good, 5.42 h)	71.1° 01:10	5.43	65%	78.9°
2034-07-25 Tue	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:10	5.48	74%	69.8°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-07-09&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.