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: 11-10 (91), 11-11 (89), 11-12 (88), 11-13 (87), 11-14 (85) — by astronomy; check the weather when the night is within four days.

2042-11-10astronomy score per night — click a bar for that night2042-12-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-11-10 Mon	91	—	unknown	18:45–22:10 (good, 3.42 h)	71.1° 17:05	10.81	3%	98.8°
2042-11-11 Tue	89	—	unknown	18:45–22:05 (good, 3.33 h)	71.1° 17:00	10.84	1%	90.7°
2042-11-12 Wed	88	—	unknown	18:40–22:00 (good, 3.33 h)	71.1° 16:55	10.87	0%	82.6°
2042-11-13 Thu	87	—	unknown	18:40–22:00 (good, 3.33 h)	71.1° 16:50	10.9	1%	74.6°
2042-11-14 Fri	85	—	unknown	18:40–21:55 (good, 3.25 h)	71.1° 16:50	10.93	4%	67.0°
2042-11-15 Sat	84	—	unknown	18:40–21:50 (good, 3.17 h)	71.1° 16:45	10.96	9%	59.9°
2042-11-16 Sun	78	—	unknown	18:40–21:45 (good, 3.08 h)	71.1° 16:40	10.99	15%	53.9°
2042-11-17 Mon	69	—	unknown	18:40–21:45 (good, 3.08 h)	71.1° 16:35	11.02	23%	49.4°
2042-11-18 Tue	59	—	unknown	18:40–21:40 (good, 3.0 h)	71.1° 16:35	11.05	32%	47.1°
2042-11-19 Wed	50	—	unknown	18:35–21:20 (good, 2.75 h)	71.1° 16:30	11.07	43%	47.5°
2042-11-20 Thu	41	—	unknown	18:35–21:05 (good, 2.5 h)	71.1° 16:25	11.1	54%	50.7°
2042-11-21 Fri	35	—	unknown	18:35–19:55 (good, 1.33 h)	71.1° 16:20	11.12	64%	56.4°
2042-11-22 Sat	31	—	unknown	18:35–19:15 (good, 0.67 h)	71.1° 16:15	11.15	75%	64.0°
2042-11-23 Sun	29	—	unknown	18:35–19:05 (good, 0.5 h)	71.1° 16:15	11.17	84%	73.0°
2042-11-24 Mon	31	—	unknown	18:35–19:25 (good, 0.83 h)	71.1° 16:10	11.19	92%	82.8°
2042-11-25 Tue	35	—	unknown	18:35–20:00 (good, 1.42 h)	71.1° 16:05	11.22	97%	93.1°
2042-11-26 Wed	41	—	unknown	18:35–20:40 (good, 2.08 h)	71.1° 16:00	11.24	100%	103.2°
2042-11-27 Thu	46	—	unknown	18:35–20:45 (good, 2.17 h)	71.1° 15:55	11.26	99%	112.7°
2042-11-28 Fri	51	—	unknown	18:35–20:50 (good, 2.25 h)	71.1° 15:55	11.28	96%	121.1°
2042-11-29 Sat	56	—	unknown	18:35–20:45 (good, 2.17 h)	71.1° 15:50	11.3	90%	127.6°
2042-11-30 Sun	57	—	unknown	18:35–20:45 (good, 2.17 h)	71.1° 15:45	11.32	83%	131.8°
2042-12-01 Mon	56	—	unknown	18:35–20:50 (good, 2.25 h)	71.1° 15:40	11.33	74%	133.1°
2042-12-02 Tue	55	—	unknown	18:35–20:45 (good, 2.17 h)	71.1° 15:35	11.35	64%	131.7°
2042-12-03 Wed	53	—	unknown	18:35–20:40 (good, 2.08 h)	71.1° 15:35	11.37	55%	128.0°
2042-12-04 Thu	52	—	unknown	18:35–20:35 (good, 2.0 h)	71.1° 15:30	11.38	45%	122.6°
2042-12-05 Fri	50	—	unknown	18:35–20:30 (good, 1.92 h)	71.1° 15:25	11.4	36%	116.1°
2042-12-06 Sat	48	—	unknown	18:35–20:30 (good, 1.92 h)	71.1° 15:20	11.41	27%	108.8°
2042-12-07 Sun	46	—	unknown	18:35–20:25 (good, 1.83 h)	71.1° 15:20	11.42	19%	101.1°
2042-12-08 Mon	44	—	unknown	18:35–20:20 (good, 1.75 h)	71.1° 15:15	11.43	12%	93.0°
2042-12-09 Tue	43	—	unknown	18:35–20:15 (good, 1.67 h)	71.1° 15:10	11.44	7%	84.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-11-10&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.