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: 10-10 (100), 10-11 (100), 10-12 (100), 10-13 (100), 10-14 (100) — by astronomy; check the weather when the night is within four days.

2036-10-10astronomy score per night — click a bar for that night2036-11-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-10-10 Fri	100	—	unknown	20:20–01:05 (good, 4.75 h)	71.1° 20:05	9.63	70%	125.3°
2036-10-11 Sat	100	—	unknown	20:20–01:00 (good, 4.67 h)	71.1° 20:00	9.67	59%	132.4°
2036-10-12 Sun	100	—	unknown	20:20–01:00 (good, 4.67 h)	71.1° 19:55	9.71	48%	137.2°
2036-10-13 Mon	100	—	unknown	20:15–01:00 (good, 4.75 h)	71.1° 19:50	9.76	37%	138.5°
2036-10-14 Tue	100	—	unknown	20:15–00:55 (good, 4.67 h)	71.1° 19:50	9.8	26%	136.0°
2036-10-15 Wed	100	—	unknown	20:15–00:50 (good, 4.58 h)	71.1° 19:45	9.85	17%	130.0°
2036-10-16 Thu	100	—	unknown	20:10–00:45 (good, 4.58 h)	71.1° 19:40	9.89	9%	121.8°
2036-10-17 Fri	100	—	unknown	20:10–00:45 (good, 4.58 h)	71.1° 19:35	9.93	3%	112.1°
2036-10-18 Sat	100	—	unknown	20:10–00:40 (good, 4.5 h)	71.1° 19:30	9.97	1%	101.7°
2036-10-19 Sun	100	—	unknown	20:10–00:35 (good, 4.42 h)	71.1° 19:30	10.02	0%	91.1°
2036-10-20 Mon	100	—	unknown	20:05–00:30 (good, 4.42 h)	71.1° 19:25	10.06	3%	80.8°
2036-10-21 Tue	100	—	unknown	20:05–00:25 (good, 4.33 h)	71.1° 19:20	10.1	7%	70.9°
2036-10-22 Wed	100	—	unknown	20:05–00:25 (good, 4.33 h)	71.1° 19:15	10.14	14%	61.9°
2036-10-23 Thu	97	—	unknown	20:05–00:20 (good, 4.25 h)	71.1° 19:15	10.18	21%	54.0°
2036-10-24 Fri	91	—	unknown	20:00–00:15 (good, 4.25 h)	71.1° 19:10	10.22	30%	47.6°
2036-10-25 Sat	80	—	unknown	20:00–00:10 (good, 4.17 h)	71.1° 19:05	10.26	39%	43.4°
2036-10-26 Sun	64	—	unknown	19:00–22:50 (good, 3.83 h)	71.1° 18:00	10.3	49%	41.6°
2036-10-27 Mon	53	—	unknown	18:55–22:35 (good, 3.67 h)	71.1° 17:55	10.34	58%	42.6°
2036-10-28 Tue	45	—	unknown	18:55–20:55 (good, 2.0 h)	71.1° 17:55	10.37	67%	46.1°
2036-10-29 Wed	40	—	unknown	18:55–20:00 (good, 1.08 h)	71.1° 17:50	10.41	76%	51.6°
2036-10-30 Thu	39	—	unknown	18:55–19:45 (good, 0.83 h)	71.1° 17:45	10.45	83%	58.7°
2036-10-31 Fri	39	—	unknown	18:55–19:50 (good, 0.92 h)	71.1° 17:40	10.49	90%	66.8°
2036-11-01 Sat	43	—	unknown	18:50–20:15 (good, 1.42 h)	71.1° 17:35	10.52	95%	75.7°
2036-11-02 Sun	49	—	unknown	18:50–20:55 (good, 2.08 h)	71.1° 17:35	10.56	98%	85.1°
2036-11-03 Mon	58	—	unknown	18:50–21:35 (good, 2.75 h)	71.1° 17:30	10.59	100%	94.8°
2036-11-04 Tue	67	—	unknown	18:50–22:10 (good, 3.33 h)	71.1° 17:25	10.63	99%	104.6°
2036-11-05 Wed	77	—	unknown	18:45–22:15 (good, 3.5 h)	71.1° 17:20	10.66	96%	114.2°
2036-11-06 Thu	89	—	unknown	18:45–22:15 (good, 3.5 h)	71.1° 17:20	10.7	90%	123.1°
2036-11-07 Fri	89	—	unknown	18:45–22:10 (good, 3.42 h)	71.1° 17:15	10.73	83%	130.7°
2036-11-08 Sat	91	—	unknown	18:45–22:10 (good, 3.42 h)	71.1° 17:10	10.76	73%	136.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-10-10&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.