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: 10-30 (100), 10-31 (97), 11-01 (85), 11-15 (80), 11-16 (80) — by astronomy; check the weather when the night is within four days.

2038-10-30astronomy score per night — click a bar for that night2038-11-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-10-30 Sat	100	—	unknown	19:55–23:55 (good, 4.0 h)	71.1° 18:45	10.43	11%	61.9°
2038-10-31 Sun	97	—	unknown	18:55–22:50 (good, 3.92 h)	71.1° 17:45	10.47	20%	54.0°
2038-11-01 Mon	85	—	unknown	18:50–22:45 (good, 3.92 h)	71.1° 17:40	10.5	29%	48.2°
2038-11-02 Tue	71	—	unknown	18:50–22:40 (good, 3.83 h)	71.1° 17:35	10.54	40%	45.4°
2038-11-03 Wed	58	—	unknown	18:50–22:20 (good, 3.5 h)	71.1° 17:30	10.58	50%	45.5°
2038-11-04 Thu	49	—	unknown	18:50–21:45 (good, 2.92 h)	71.1° 17:30	10.61	60%	48.5°
2038-11-05 Fri	42	—	unknown	18:50–20:30 (good, 1.67 h)	71.1° 17:25	10.65	70%	53.5°
2038-11-06 Sat	40	—	unknown	18:45–19:55 (good, 1.17 h)	71.1° 17:20	10.68	79%	60.0°
2038-11-07 Sun	39	—	unknown	18:45–19:50 (good, 1.08 h)	71.1° 17:15	10.71	86%	67.4°
2038-11-08 Mon	40	—	unknown	18:45–20:00 (good, 1.25 h)	71.1° 17:10	10.75	92%	75.4°
2038-11-09 Tue	44	—	unknown	18:45–20:25 (good, 1.67 h)	71.1° 17:10	10.78	96%	83.6°
2038-11-10 Wed	49	—	unknown	18:45–20:55 (good, 2.17 h)	71.1° 17:05	10.81	99%	92.0°
2038-11-11 Thu	56	—	unknown	18:45–21:35 (good, 2.83 h)	71.1° 17:00	10.84	100%	100.3°
2038-11-12 Fri	63	—	unknown	18:40–21:40 (good, 3.0 h)	71.1° 16:55	10.87	99%	108.3°
2038-11-13 Sat	69	—	unknown	18:40–21:45 (good, 3.08 h)	71.1° 16:50	10.9	96%	116.0°
2038-11-14 Sun	79	—	unknown	18:40–21:45 (good, 3.08 h)	71.1° 16:50	10.93	92%	122.9°
2038-11-15 Mon	80	—	unknown	18:40–21:40 (good, 3.0 h)	71.1° 16:45	10.96	86%	128.7°
2038-11-16 Tue	80	—	unknown	18:40–21:40 (good, 3.0 h)	71.1° 16:40	10.99	79%	132.9°
2038-11-17 Wed	80	—	unknown	18:40–21:40 (good, 3.0 h)	71.1° 16:35	11.02	70%	134.8°
2038-11-18 Thu	78	—	unknown	18:40–21:40 (good, 3.0 h)	71.1° 16:30	11.04	60%	134.0°
2038-11-19 Fri	77	—	unknown	18:35–21:35 (good, 3.0 h)	71.1° 16:30	11.07	50%	130.4°
2038-11-20 Sat	76	—	unknown	18:35–21:30 (good, 2.92 h)	71.1° 16:25	11.1	39%	124.5°
2038-11-21 Sun	74	—	unknown	18:35–21:25 (good, 2.83 h)	71.1° 16:20	11.12	29%	116.7°
2038-11-22 Mon	73	—	unknown	18:35–21:25 (good, 2.83 h)	71.1° 16:15	11.15	19%	107.5°
2038-11-23 Tue	70	—	unknown	18:35–21:20 (good, 2.75 h)	71.1° 16:15	11.17	10%	97.4°
2038-11-24 Wed	69	—	unknown	18:35–21:15 (good, 2.67 h)	71.1° 16:10	11.19	4%	86.8°
2038-11-25 Thu	67	—	unknown	18:35–21:10 (good, 2.58 h)	71.1° 16:05	11.21	1%	76.3°
2038-11-26 Fri	65	—	unknown	18:35–21:05 (good, 2.5 h)	71.1° 16:00	11.24	0%	66.2°
2038-11-27 Sat	63	—	unknown	18:35–21:05 (good, 2.5 h)	71.1° 15:55	11.26	3%	57.3°
2038-11-28 Sun	61	—	unknown	18:35–21:00 (good, 2.42 h)	71.1° 15:55	11.28	8%	50.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-10-30&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.