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: 12-06 (47), 12-05 (46), 12-07 (46), 12-08 (44), 12-04 (42) — by astronomy; check the weather when the night is within four days.

2036-12-04astronomy score per night — click a bar for that night2037-01-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-12-04 Thu	42	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:30	11.39	98%	128.4°
2036-12-05 Fri	46	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 15:25	11.4	93%	134.7°
2036-12-06 Sat	47	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 15:20	11.41	86%	137.9°
2036-12-07 Sun	46	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 15:15	11.43	77%	137.2°
2036-12-08 Mon	44	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 15:10	11.44	66%	132.8°
2036-12-09 Tue	42	—	unknown	18:35–20:15 (good, 1.67 h)	71.1° 15:10	11.45	55%	125.7°
2036-12-10 Wed	41	—	unknown	18:35–20:10 (good, 1.58 h)	71.1° 15:05	11.46	44%	117.0°
2036-12-11 Thu	39	—	unknown	18:35–20:05 (good, 1.5 h)	71.1° 15:00	11.47	33%	107.4°
2036-12-12 Fri	38	—	unknown	18:35–20:00 (good, 1.42 h)	71.1° 14:55	11.48	23%	97.4°
2036-12-13 Sat	36	—	unknown	18:35–20:00 (good, 1.42 h)	71.1° 14:50	11.48	15%	87.4°
2036-12-14 Sun	34	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 14:50	11.49	8%	77.6°
2036-12-15 Mon	34	—	unknown	18:35–19:50 (good, 1.25 h)	71.1° 14:45	11.49	3%	68.2°
2036-12-16 Tue	32	—	unknown	18:35–19:45 (good, 1.17 h)	71.1° 14:40	11.5	1%	59.6°
2036-12-17 Wed	30	—	unknown	18:35–19:45 (good, 1.17 h)	71.1° 14:35	11.5	0%	52.2°
2036-12-18 Thu	29	—	unknown	18:35–19:40 (good, 1.08 h)	71.1° 14:35	11.5	2%	46.4°
2036-12-19 Fri	27	—	unknown	18:35–19:35 (good, 1.0 h)	71.1° 14:30	11.51	5%	42.9°
2036-12-20 Sat	25	—	unknown	18:35–19:30 (good, 0.92 h)	71.1° 14:25	11.51	10%	42.0°
2036-12-21 Sun	21	—	unknown	18:35–19:20 (good, 0.75 h)	71.1° 14:20	11.51	16%	44.0°
2036-12-22 Mon	18	—	unknown	18:35–19:15 (good, 0.67 h)	71.1° 14:15	11.51	24%	48.2°
2036-12-23 Tue	15	—	unknown	18:40–19:05 (good, 0.42 h)	71.1° 14:15	11.5	32%	54.2°
2036-12-24 Wed	13	—	unknown	18:40–18:55 (good, 0.25 h)	71.1° 14:10	11.5	42%	61.4°
2036-12-25 Thu	11	—	unknown	18:40–18:50 (good, 0.17 h)	71.1° 14:05	11.5	51%	69.6°
2036-12-26 Fri	10	—	unknown	18:05–19:35 (marginal, 1.5 h)	71.1° 14:00	11.49	61%	78.3°
2036-12-27 Sat	9	—	unknown	18:05–19:30 (marginal, 1.42 h)	71.1° 13:55	11.49	70%	87.5°
2036-12-28 Sun	8	—	unknown	18:40–19:25 (marginal, 0.75 h)	71.1° 13:55	11.48	79%	97.1°
2036-12-29 Mon	8	—	unknown	18:40–19:25 (marginal, 0.75 h)	71.1° 13:50	11.47	87%	106.8°
2036-12-30 Tue	8	—	unknown	18:10–19:20 (marginal, 1.17 h)	71.1° 13:45	11.47	94%	116.3°
2036-12-31 Wed	6	—	unknown	18:45–19:15 (marginal, 0.5 h)	71.1° 13:40	11.46	98%	125.2°
2037-01-01 Thu	6	—	unknown	18:45–19:10 (marginal, 0.42 h)	71.1° 13:35	11.45	100%	132.5°
2037-01-02 Fri	5	—	unknown	18:45–19:05 (marginal, 0.33 h)	71.1° 13:35	11.44	99%	137.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-12-04&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.