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: 12-05 (48), 12-06 (48), 12-07 (46), 12-08 (45), 12-03 (44) — by astronomy; check the weather when the night is within four days.

2047-11-27astronomy score per night — click a bar for that night2047-12-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-11-27 Wed	25	—	unknown	18:00–21:20 (marginal, 3.33 h)	71.1° 16:00	11.25	82%	69.7°
2047-11-28 Thu	26	—	unknown	18:35–18:55 (good, 0.33 h)	71.2° 15:55	11.27	89%	78.7°
2047-11-29 Fri	29	—	unknown	18:35–19:25 (good, 0.83 h)	71.2° 15:50	11.29	94%	87.8°
2047-11-30 Sat	32	—	unknown	18:35–20:00 (good, 1.42 h)	71.2° 15:45	11.31	98%	96.9°
2047-12-01 Sun	37	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:40	11.33	100%	106.0°
2047-12-02 Mon	41	—	unknown	18:35–20:30 (good, 1.92 h)	71.2° 15:40	11.35	100%	114.7°
2047-12-03 Tue	44	—	unknown	18:35–20:30 (good, 1.92 h)	71.2° 15:35	11.36	98%	123.0°
2047-12-04 Wed	44	—	unknown	18:35–20:30 (good, 1.92 h)	71.2° 15:30	11.38	95%	130.4°
2047-12-05 Thu	48	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:25	11.39	90%	136.3°
2047-12-06 Fri	48	—	unknown	18:35–20:30 (good, 1.92 h)	71.1° 15:25	11.41	83%	140.0°
2047-12-07 Sat	46	—	unknown	18:35–20:25 (good, 1.83 h)	71.2° 15:20	11.42	74%	140.6°
2047-12-08 Sun	45	—	unknown	18:35–20:20 (good, 1.75 h)	71.2° 15:15	11.43	65%	137.8°
2047-12-09 Mon	44	—	unknown	18:35–20:15 (good, 1.67 h)	71.2° 15:10	11.44	55%	132.1°
2047-12-10 Tue	42	—	unknown	18:35–20:15 (good, 1.67 h)	71.1° 15:05	11.45	44%	124.2°
2047-12-11 Wed	40	—	unknown	18:35–20:10 (good, 1.58 h)	71.1° 15:05	11.46	33%	114.7°
2047-12-12 Thu	39	—	unknown	18:35–20:05 (good, 1.5 h)	71.2° 15:00	11.47	22%	104.1°
2047-12-13 Fri	38	—	unknown	18:35–20:00 (good, 1.42 h)	71.2° 14:55	11.48	14%	92.8°
2047-12-14 Sat	36	—	unknown	18:35–20:00 (good, 1.42 h)	71.2° 14:50	11.48	6%	81.3°
2047-12-15 Sun	34	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 14:45	11.49	2%	69.9°
2047-12-16 Mon	33	—	unknown	18:35–19:50 (good, 1.25 h)	71.2° 14:45	11.5	0%	59.1°
2047-12-17 Tue	32	—	unknown	18:35–19:45 (good, 1.17 h)	71.2° 14:40	11.5	1%	49.8°
2047-12-18 Wed	30	—	unknown	18:35–19:40 (good, 1.08 h)	71.2° 14:35	11.5	5%	42.9°
2047-12-19 Thu	26	—	unknown	18:35–19:35 (good, 1.0 h)	71.1° 14:30	11.51	12%	39.5°
2047-12-20 Fri	22	—	unknown	18:35–19:25 (good, 0.83 h)	71.1° 14:30	11.51	20%	40.1°
2047-12-21 Sat	18	—	unknown	18:35–19:15 (good, 0.67 h)	71.2° 14:25	11.51	29%	44.3°
2047-12-22 Sun	15	—	unknown	18:35–19:05 (good, 0.5 h)	71.2° 14:20	11.51	39%	50.8°
2047-12-23 Mon	12	—	unknown	18:40–18:50 (good, 0.17 h)	71.2° 14:15	11.51	48%	58.7°
2047-12-24 Tue	10	—	unknown	18:40–19:45 (marginal, 1.08 h)	71.1° 14:10	11.5	58%	67.2°
2047-12-25 Wed	9	—	unknown	18:40–19:40 (marginal, 1.0 h)	71.1° 14:10	11.5	68%	76.2°
2047-12-26 Thu	9	—	unknown	18:40–19:35 (marginal, 0.92 h)	71.2° 14:05	11.5	76%	85.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-11-27&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.