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: 11-16 (80), 11-17 (80), 11-18 (78), 11-19 (77), 11-20 (76) — by astronomy; check the weather when the night is within four days.

2038-11-16astronomy score per night — click a bar for that night2038-12-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2038-11-29 Mon	55	—	unknown	18:35–20:55 (good, 2.33 h)	71.1° 15:50	11.3	15%	46.2°
2038-11-30 Tue	47	—	unknown	18:35–20:45 (good, 2.17 h)	71.1° 15:45	11.31	24%	45.3°
2038-12-01 Wed	40	—	unknown	18:35–20:35 (good, 2.0 h)	71.1° 15:40	11.33	34%	47.5°
2038-12-02 Thu	34	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:35	11.35	44%	52.1°
2038-12-03 Fri	29	—	unknown	18:35–20:15 (good, 1.67 h)	71.1° 15:35	11.37	54%	58.3°
2038-12-04 Sat	26	—	unknown	18:35–19:35 (good, 1.0 h)	71.1° 15:30	11.38	64%	65.5°
2038-12-05 Sun	24	—	unknown	18:35–19:15 (good, 0.67 h)	71.1° 15:25	11.39	72%	73.4°
2038-12-06 Mon	24	—	unknown	18:35–19:15 (good, 0.67 h)	71.1° 15:20	11.41	80%	81.5°
2038-12-07 Tue	24	—	unknown	18:35–19:25 (good, 0.83 h)	71.1° 15:20	11.42	87%	89.8°
2038-12-08 Wed	26	—	unknown	18:35–19:50 (good, 1.25 h)	71.1° 15:15	11.43	93%	98.1°
2038-12-09 Thu	28	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 15:10	11.44	97%	106.3°
2038-12-10 Fri	30	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 15:05	11.45	99%	114.1°
2038-12-11 Sat	32	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 15:00	11.46	100%	121.3°
2038-12-12 Sun	31	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 15:00	11.47	99%	127.4°
2038-12-13 Mon	32	—	unknown	18:35–19:50 (good, 1.25 h)	71.1° 14:55	11.48	96%	132.0°
2038-12-14 Tue	35	—	unknown	18:35–19:50 (good, 1.25 h)	71.1° 14:50	11.49	90%	134.5°
2038-12-15 Wed	34	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 14:45	11.49	84%	134.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-11-16&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.