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: 07-07 (100), 07-08 (100), 07-09 (100), 07-10 (100), 07-11 (100) — by astronomy; check the weather when the night is within four days.

2034-06-30astronomy score per night — click a bar for that night2034-07-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-06-30 Fri	43	—	unknown	23:10–03:45 (marginal, 4.58 h)	71.1° 02:45	4.52	99%	50.7°
2034-07-01 Sat	35	—	unknown	23:10–03:45 (marginal, 4.58 h)	71.1° 02:45	4.54	100%	44.1°
2034-07-02 Sun	32	—	unknown	23:10–03:45 (marginal, 4.58 h)	71.1° 02:40	4.56	98%	39.7°
2034-07-03 Mon	36	—	unknown	23:10–03:45 (marginal, 4.58 h)	71.1° 02:35	4.59	95%	38.4°
2034-07-04 Tue	45	—	unknown	23:10–03:45 (marginal, 4.58 h)	71.1° 02:30	4.61	89%	40.7°
2034-07-05 Wed	82	—	unknown	23:10–01:55 (good, 2.75 h)	71.1° 02:25	4.64	82%	46.2°
2034-07-06 Thu	95	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:25	4.67	73%	54.0°
2034-07-07 Fri	100	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:20	4.7	63%	63.4°
2034-07-08 Sat	100	—	unknown	23:05–03:50 (good, 4.75 h)	71.1° 02:15	4.73	52%	73.7°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-06-30&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.