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: 10-15 (100), 10-16 (100), 10-17 (100), 10-18 (100), 10-19 (100) — by astronomy; check the weather when the night is within four days.

2033-10-15astronomy score per night — click a bar for that night2033-11-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2033-10-28 Fri	89	—	unknown	19:55–00:00 (good, 4.08 h)	71.1° 18:55	10.36	27%	45.7°
2033-10-29 Sat	75	—	unknown	19:55–23:55 (good, 4.0 h)	71.1° 18:50	10.4	37%	40.1°
2033-10-30 Sun	59	—	unknown	18:55–22:35 (good, 3.67 h)	71.1° 17:45	10.44	47%	37.5°
2033-10-31 Mon	47	—	unknown	18:55–21:40 (good, 2.75 h)	71.1° 17:40	10.48	58%	38.8°
2033-11-01 Tue	39	—	unknown	18:50–19:45 (good, 0.92 h)	71.1° 17:40	10.51	69%	43.9°
2033-11-02 Wed	34	—	unknown	18:50–22:55 (marginal, 4.08 h)	71.1° 17:35	10.55	79%	51.9°
2033-11-03 Thu	34	—	unknown	18:50–18:55 (good, 0.08 h)	71.1° 17:30	10.58	88%	61.9°
2033-11-04 Fri	38	—	unknown	18:50–19:45 (good, 0.92 h)	71.1° 17:25	10.62	94%	73.2°
2033-11-05 Sat	46	—	unknown	18:50–20:35 (good, 1.75 h)	71.1° 17:25	10.65	99%	85.1°
2033-11-06 Sun	57	—	unknown	18:45–21:35 (good, 2.83 h)	71.1° 17:20	10.69	100%	97.1°
2033-11-07 Mon	68	—	unknown	18:45–22:00 (good, 3.25 h)	71.1° 17:15	10.72	98%	108.8°
2033-11-08 Tue	85	—	unknown	18:45–22:05 (good, 3.33 h)	71.1° 17:10	10.75	94%	119.7°
2033-11-09 Wed	87	—	unknown	18:45–22:05 (good, 3.33 h)	71.1° 17:05	10.79	87%	129.3°
2033-11-10 Thu	88	—	unknown	18:45–22:00 (good, 3.25 h)	71.1° 17:05	10.82	79%	136.9°
2033-11-11 Fri	89	—	unknown	18:40–22:00 (good, 3.33 h)	71.1° 17:00	10.85	69%	141.4°
2033-11-12 Sat	88	—	unknown	18:40–22:00 (good, 3.33 h)	71.1° 16:55	10.88	59%	142.4°
2033-11-13 Sun	86	—	unknown	18:40–21:55 (good, 3.25 h)	71.1° 16:50	10.91	49%	139.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-10-15&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.