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: 11-18 (78), 11-19 (77), 11-20 (76), 11-21 (74), 11-22 (72) — by astronomy; check the weather when the night is within four days.

2030-11-18astronomy score per night — click a bar for that night2030-12-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-11-18 Mon	78	—	unknown	18:40–21:40 (good, 3.0 h)	71.1° 16:30	11.04	44%	137.2°
2030-11-19 Tue	77	—	unknown	18:35–21:35 (good, 3.0 h)	71.1° 16:30	11.07	34%	130.3°
2030-11-20 Wed	76	—	unknown	18:35–21:30 (good, 2.92 h)	71.1° 16:25	11.1	24%	121.6°
2030-11-21 Thu	74	—	unknown	18:35–21:25 (good, 2.83 h)	71.1° 16:20	11.12	16%	111.4°
2030-11-22 Fri	72	—	unknown	18:35–21:25 (good, 2.83 h)	71.1° 16:15	11.14	8%	100.4°
2030-11-23 Sat	70	—	unknown	18:35–21:20 (good, 2.75 h)	71.1° 16:15	11.17	3%	88.7°
2030-11-24 Sun	69	—	unknown	18:35–21:15 (good, 2.67 h)	71.1° 16:10	11.19	0%	76.8°
2030-11-25 Mon	67	—	unknown	18:35–21:10 (good, 2.58 h)	71.1° 16:05	11.21	1%	65.2°
2030-11-26 Tue	65	—	unknown	18:35–21:05 (good, 2.5 h)	71.1° 16:00	11.24	4%	54.4°
2030-11-27 Wed	60	—	unknown	18:35–21:05 (good, 2.5 h)	71.1° 15:55	11.26	10%	45.4°
2030-11-28 Thu	53	—	unknown	18:35–21:00 (good, 2.42 h)	71.1° 15:55	11.28	18%	39.4°
2030-11-29 Fri	44	—	unknown	18:35–20:45 (good, 2.17 h)	71.1° 15:50	11.3	28%	37.5°
2030-11-30 Sat	36	—	unknown	18:35–20:30 (good, 1.92 h)	71.1° 15:45	11.31	39%	40.0°
2030-12-01 Sun	29	—	unknown	18:35–20:00 (good, 1.42 h)	71.1° 15:40	11.33	50%	45.8°
2030-12-02 Mon	25	—	unknown	18:35–19:00 (good, 0.42 h)	71.1° 15:35	11.35	60%	53.6°
2030-12-03 Tue	22	—	unknown	18:35–21:00 (marginal, 2.42 h)	71.1° 15:35	11.36	70%	62.5°
2030-12-04 Wed	22	—	unknown	18:35–20:55 (marginal, 2.33 h)	71.1° 15:30	11.38	78%	71.8°
2030-12-05 Thu	22	—	unknown	18:35–18:50 (good, 0.25 h)	71.1° 15:25	11.39	86%	81.3°
2030-12-06 Fri	24	—	unknown	18:35–19:20 (good, 0.75 h)	71.1° 15:20	11.41	92%	90.9°
2030-12-07 Sat	27	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 15:20	11.42	96%	100.4°
2030-12-08 Sun	30	—	unknown	18:35–20:00 (good, 1.42 h)	71.1° 15:15	11.43	99%	109.6°
2030-12-09 Mon	34	—	unknown	18:35–20:05 (good, 1.5 h)	71.1° 15:10	11.44	100%	118.5°
2030-12-10 Tue	34	—	unknown	18:35–20:00 (good, 1.42 h)	71.1° 15:05	11.45	99%	126.6°
2030-12-11 Wed	34	—	unknown	18:35–20:00 (good, 1.42 h)	71.1° 15:00	11.46	96%	133.7°
2030-12-12 Thu	37	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 15:00	11.47	92%	139.2°
2030-12-13 Fri	37	—	unknown	18:35–20:00 (good, 1.42 h)	71.1° 14:55	11.48	86%	142.2°
2030-12-14 Sat	36	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 14:50	11.49	79%	142.0°
2030-12-15 Sun	34	—	unknown	18:35–19:50 (good, 1.25 h)	71.1° 14:45	11.49	70%	138.6°
2030-12-16 Mon	32	—	unknown	18:35–19:50 (good, 1.25 h)	71.1° 14:40	11.5	61%	132.6°
2030-12-17 Tue	31	—	unknown	18:35–19:45 (good, 1.17 h)	71.1° 14:40	11.5	51%	124.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-11-18&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.