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: 10-19 (100), 10-20 (100), 10-21 (100), 10-22 (100), 10-23 (100) — by astronomy; check the weather when the night is within four days.

2035-10-07astronomy score per night — click a bar for that night2035-11-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-10-07 Sun	95	—	unknown	20:30–01:25 (good, 4.92 h)	71.1° 20:20	9.45	36%	51.9°
2035-10-08 Mon	90	—	unknown	20:25–01:20 (good, 4.92 h)	71.1° 20:15	9.5	45%	45.7°
2035-10-09 Tue	82	—	unknown	20:25–01:15 (good, 4.83 h)	71.1° 20:10	9.55	55%	41.5°
2035-10-10 Wed	57	—	unknown	20:25–00:30 (good, 4.08 h)	71.1° 20:05	9.59	64%	39.8°
2035-10-11 Thu	46	—	unknown	20:20–01:35 (marginal, 5.25 h)	71.1° 20:05	9.64	73%	41.0°
2035-10-12 Fri	40	—	unknown	20:20–01:20 (marginal, 5.0 h)	71.1° 20:00	9.68	81%	45.2°
2035-10-13 Sat	38	—	unknown	20:20–01:10 (marginal, 4.83 h)	71.1° 19:55	9.73	89%	51.6°
2035-10-14 Sun	40	—	unknown	19:45–01:05 (marginal, 5.33 h)	71.1° 19:50	9.77	94%	59.8°
2035-10-15 Mon	46	—	unknown	20:15–21:35 (good, 1.33 h)	71.1° 19:45	9.81	98%	69.2°
2035-10-16 Tue	55	—	unknown	20:15–22:25 (good, 2.17 h)	71.1° 19:45	9.86	100%	79.5°
2035-10-17 Wed	68	—	unknown	20:10–23:25 (good, 3.25 h)	71.1° 19:40	9.9	99%	90.2°
2035-10-18 Thu	81	—	unknown	20:10–00:15 (good, 4.08 h)	71.1° 19:35	9.94	96%	101.1°
2035-10-19 Fri	100	—	unknown	20:10–00:20 (good, 4.17 h)	71.1° 19:30	9.98	90%	111.7°
2035-10-20 Sat	100	—	unknown	20:10–00:25 (good, 4.25 h)	71.1° 19:25	10.03	82%	121.7°
2035-10-21 Sun	100	—	unknown	20:05–00:25 (good, 4.33 h)	71.1° 19:25	10.07	72%	130.4°
2035-10-22 Mon	100	—	unknown	20:05–00:20 (good, 4.25 h)	71.1° 19:20	10.11	61%	136.9°
2035-10-23 Tue	100	—	unknown	20:05–00:20 (good, 4.25 h)	71.1° 19:15	10.15	50%	140.0°
2035-10-24 Wed	100	—	unknown	20:00–00:20 (good, 4.33 h)	71.1° 19:10	10.19	38%	139.1°
2035-10-25 Thu	100	—	unknown	20:00–00:15 (good, 4.25 h)	71.1° 19:10	10.23	28%	134.6°
2035-10-26 Fri	100	—	unknown	20:00–00:10 (good, 4.17 h)	71.1° 19:05	10.27	19%	127.5°
2035-10-27 Sat	100	—	unknown	20:00–00:05 (good, 4.08 h)	71.1° 19:00	10.31	11%	118.9°
2035-10-28 Sun	100	—	unknown	18:55–23:00 (good, 4.08 h)	71.1° 17:55	10.35	5%	109.5°
2035-10-29 Mon	100	—	unknown	18:55–23:00 (good, 4.08 h)	71.1° 17:50	10.38	2%	99.7°
2035-10-30 Tue	100	—	unknown	18:55–22:55 (good, 4.0 h)	71.1° 17:50	10.42	0%	89.9°
2035-10-31 Wed	100	—	unknown	18:55–22:50 (good, 3.92 h)	71.1° 17:45	10.46	1%	80.2°
2035-11-01 Thu	100	—	unknown	18:50–22:45 (good, 3.92 h)	71.1° 17:40	10.49	3%	70.9°
2035-11-02 Fri	100	—	unknown	18:50–22:45 (good, 3.92 h)	71.1° 17:35	10.53	8%	62.2°
2035-11-03 Sat	95	—	unknown	18:50–22:40 (good, 3.83 h)	71.1° 17:30	10.57	14%	54.4°
2035-11-04 Sun	86	—	unknown	18:50–22:35 (good, 3.75 h)	71.1° 17:30	10.6	21%	47.7°
2035-11-05 Mon	77	—	unknown	18:50–22:30 (good, 3.67 h)	71.1° 17:25	10.64	29%	42.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-10-07&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.