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: 10-31 (100), 11-01 (100), 11-02 (100), 10-30 (99), 11-03 (99) — by astronomy; check the weather when the night is within four days.

2034-10-28astronomy score per night — click a bar for that night2034-11-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-10-28 Sat	76	—	unknown	19:55–23:40 (good, 3.75 h)	71.1° 18:55	10.35	97%	105.2°
2034-10-29 Sun	95	—	unknown	18:55–22:45 (good, 3.83 h)	71.1° 17:50	10.39	91%	116.5°
2034-10-30 Mon	99	—	unknown	18:55–22:45 (good, 3.83 h)	71.1° 17:45	10.43	84%	126.6°
2034-10-31 Tue	100	—	unknown	18:55–22:45 (good, 3.83 h)	71.1° 17:45	10.47	74%	134.8°
2034-11-01 Wed	100	—	unknown	18:50–22:40 (good, 3.83 h)	71.1° 17:40	10.5	63%	140.0°
2034-11-02 Thu	100	—	unknown	18:50–22:40 (good, 3.83 h)	71.1° 17:35	10.54	52%	141.5°
2034-11-03 Fri	99	—	unknown	18:50–22:40 (good, 3.83 h)	71.1° 17:30	10.58	42%	139.0°
2034-11-04 Sat	98	—	unknown	18:50–22:35 (good, 3.75 h)	71.1° 17:25	10.61	32%	133.6°
2034-11-05 Sun	96	—	unknown	18:50–22:30 (good, 3.67 h)	71.1° 17:25	10.64	23%	126.3°
2034-11-06 Mon	96	—	unknown	18:45–22:25 (good, 3.67 h)	71.1° 17:20	10.68	15%	117.9°
2034-11-07 Tue	95	—	unknown	18:45–22:20 (good, 3.58 h)	71.1° 17:15	10.71	9%	108.9°
2034-11-08 Wed	93	—	unknown	18:45–22:20 (good, 3.58 h)	71.1° 17:10	10.75	4%	99.6°
2034-11-09 Thu	92	—	unknown	18:45–22:15 (good, 3.5 h)	71.1° 17:10	10.78	1%	90.3°
2034-11-10 Fri	90	—	unknown	18:45–22:10 (good, 3.42 h)	71.1° 17:05	10.81	0%	81.0°
2034-11-11 Sat	89	—	unknown	18:45–22:05 (good, 3.33 h)	71.1° 17:00	10.84	1%	71.9°
2034-11-12 Sun	88	—	unknown	18:40–22:00 (good, 3.33 h)	71.1° 16:55	10.87	3%	63.2°
2034-11-13 Mon	85	—	unknown	18:40–22:00 (good, 3.33 h)	71.1° 16:50	10.9	7%	55.1°
2034-11-14 Tue	79	—	unknown	18:40–21:55 (good, 3.25 h)	71.1° 16:50	10.93	13%	48.0°
2034-11-15 Wed	72	—	unknown	18:40–21:50 (good, 3.17 h)	71.1° 16:45	10.96	20%	42.4°
2034-11-16 Thu	62	—	unknown	18:40–21:45 (good, 3.08 h)	71.1° 16:40	10.99	28%	39.2°
2034-11-17 Fri	52	—	unknown	18:40–21:25 (good, 2.75 h)	71.1° 16:35	11.02	38%	38.9°
2034-11-18 Sat	43	—	unknown	18:40–21:15 (good, 2.58 h)	71.1° 16:30	11.04	47%	42.0°
2034-11-19 Sun	37	—	unknown	18:35–20:15 (good, 1.67 h)	71.1° 16:30	11.07	58%	47.9°
2034-11-20 Mon	32	—	unknown	18:35–19:20 (good, 0.75 h)	71.1° 16:25	11.1	68%	56.1°
2034-11-21 Tue	30	—	unknown	18:35–19:10 (good, 0.58 h)	71.1° 16:20	11.12	78%	65.7°
2034-11-22 Wed	32	—	unknown	18:35–19:20 (good, 0.75 h)	71.1° 16:15	11.15	87%	76.5°
2034-11-23 Thu	35	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 16:15	11.17	94%	88.0°
2034-11-24 Fri	41	—	unknown	18:35–20:40 (good, 2.08 h)	71.1° 16:10	11.19	98%	99.8°
2034-11-25 Sat	49	—	unknown	18:35–20:55 (good, 2.33 h)	71.1° 16:05	11.21	100%	111.4°
2034-11-26 Sun	54	—	unknown	18:35–20:55 (good, 2.33 h)	71.1° 16:00	11.24	98%	122.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-10-28&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.