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: 09-28 (100), 09-29 (100), 10-10 (100), 10-11 (100), 10-12 (100) — by astronomy; check the weather when the night is within four days.

2033-09-28astronomy score per night — click a bar for that night2033-10-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-09-28 Wed	100	—	unknown	20:45–02:00 (good, 5.25 h)	71.1° 20:50	9.05	24%	68.4°
2033-09-29 Thu	100	—	unknown	20:40–01:55 (good, 5.25 h)	71.1° 20:50	9.1	32%	59.4°
2033-09-30 Fri	95	—	unknown	20:40–01:50 (good, 5.17 h)	71.1° 20:45	9.15	42%	51.1°
2033-10-01 Sat	88	—	unknown	20:35–01:45 (good, 5.17 h)	71.1° 20:40	9.19	52%	43.9°
2033-10-02 Sun	75	—	unknown	20:35–01:40 (good, 5.08 h)	71.1° 20:35	9.24	63%	38.9°
2033-10-03 Mon	47	—	unknown	20:35–02:05 (marginal, 5.5 h)	71.1° 20:30	9.29	73%	37.4°
2033-10-04 Tue	38	—	unknown	20:30–01:50 (marginal, 5.33 h)	71.1° 20:30	9.34	83%	40.1°
2033-10-05 Wed	35	—	unknown	20:30–01:35 (marginal, 5.08 h)	71.1° 20:25	9.38	91%	46.7°
2033-10-06 Thu	37	—	unknown	20:30–01:30 (marginal, 5.0 h)	71.1° 20:20	9.43	96%	56.0°
2033-10-07 Fri	46	—	unknown	20:25–21:10 (good, 0.75 h)	71.1° 20:15	9.48	100%	66.9°
2033-10-08 Sat	58	—	unknown	20:25–22:50 (good, 2.42 h)	71.1° 20:15	9.52	100%	78.7°
2033-10-09 Sun	74	—	unknown	20:25–00:00 (good, 3.58 h)	71.1° 20:10	9.57	97%	90.7°
2033-10-10 Mon	100	—	unknown	20:20–00:50 (good, 4.5 h)	71.1° 20:05	9.61	91%	102.6°
2033-10-11 Tue	100	—	unknown	20:20–00:55 (good, 4.58 h)	71.1° 20:00	9.66	83%	113.8°
2033-10-12 Wed	100	—	unknown	20:20–00:55 (good, 4.58 h)	71.1° 19:55	9.7	74%	124.0°
2033-10-13 Thu	100	—	unknown	20:15–00:55 (good, 4.67 h)	71.1° 19:55	9.75	63%	132.6°
2033-10-14 Fri	100	—	unknown	20:15–00:50 (good, 4.58 h)	71.1° 19:50	9.79	53%	139.0°
2033-10-15 Sat	100	—	unknown	20:15–00:50 (good, 4.58 h)	71.1° 19:45	9.83	43%	142.3°
2033-10-16 Sun	100	—	unknown	20:15–00:45 (good, 4.5 h)	71.1° 19:40	9.88	33%	142.0°
2033-10-17 Mon	100	—	unknown	20:10–00:45 (good, 4.58 h)	71.1° 19:35	9.92	24%	138.6°
2033-10-18 Tue	100	—	unknown	20:10–00:40 (good, 4.5 h)	71.1° 19:35	9.96	16%	132.7°
2033-10-19 Wed	100	—	unknown	20:10–00:35 (good, 4.42 h)	71.1° 19:30	10.0	10%	125.3°
2033-10-20 Thu	100	—	unknown	20:05–00:30 (good, 4.42 h)	71.1° 19:25	10.05	5%	117.0°
2033-10-21 Fri	100	—	unknown	20:05–00:30 (good, 4.42 h)	71.1° 19:20	10.09	2%	108.1°
2033-10-22 Sat	100	—	unknown	20:05–00:25 (good, 4.33 h)	71.1° 19:20	10.13	0%	98.9°
2033-10-23 Sun	100	—	unknown	20:05–00:20 (good, 4.25 h)	71.1° 19:15	10.17	0%	89.5°
2033-10-24 Mon	100	—	unknown	20:00–00:15 (good, 4.25 h)	71.1° 19:10	10.21	2%	80.0°
2033-10-25 Tue	100	—	unknown	20:00–00:10 (good, 4.17 h)	71.1° 19:05	10.25	6%	70.7°
2033-10-26 Wed	100	—	unknown	20:00–00:10 (good, 4.17 h)	71.1° 19:00	10.29	12%	61.6°
2033-10-27 Thu	97	—	unknown	20:00–00:05 (good, 4.08 h)	71.1° 19:00	10.33	19%	53.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-09-28&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.