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.

2034-09-28astronomy score per night — click a bar for that night2034-10-27

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-09-28 Thu	—	unknown	—	50.2° 13:25	9.04	99%	168.8°
2034-09-29 Fri	—	unknown	—	50.2° 13:20	9.09	95%	154.4°
2034-09-30 Sat	—	unknown	—	50.2° 13:15	9.13	89%	139.6°
2034-10-01 Sun	—	unknown	—	50.2° 13:10	9.18	80%	125.0°
2034-10-02 Mon	—	unknown	—	50.2° 13:05	9.23	70%	110.5°
2034-10-03 Tue	—	unknown	—	50.2° 13:05	9.28	59%	96.3°
2034-10-04 Wed	—	unknown	—	50.2° 13:00	9.33	48%	82.4°
2034-10-05 Thu	—	unknown	—	50.2° 12:55	9.37	37%	68.8°
2034-10-06 Fri	—	unknown	—	50.2° 12:50	9.42	27%	55.4°
2034-10-07 Sat	—	unknown	—	50.2° 12:45	9.47	18%	42.4°
2034-10-08 Sun	—	unknown	—	50.2° 12:45	9.51	11%	29.6°
2034-10-09 Mon	—	unknown	—	50.2° 12:40	9.56	6%	17.1°
2034-10-10 Tue	—	unknown	—	50.2° 12:35	9.6	2%	5.6°
2034-10-11 Wed	—	unknown	—	50.2° 12:30	9.65	0%	8.9°
2034-10-12 Thu	—	unknown	—	50.2° 12:30	9.69	0%	20.6°
2034-10-13 Fri	—	unknown	—	50.2° 12:25	9.74	2%	32.5°
2034-10-14 Sat	—	unknown	—	50.2° 12:20	9.78	6%	44.3°
2034-10-15 Sun	—	unknown	—	50.2° 12:15	9.82	12%	56.1°
2034-10-16 Mon	—	unknown	—	50.2° 12:10	9.87	18%	67.8°
2034-10-17 Tue	—	unknown	—	50.2° 12:10	9.91	26%	79.6°
2034-10-18 Wed	—	unknown	—	50.2° 12:00	9.95	35%	91.6°
2034-10-19 Thu	—	unknown	—	50.2° 12:00	9.99	44%	103.6°
2034-10-20 Fri	—	unknown	—	50.2° 11:50	10.04	54%	116.0°
2034-10-21 Sat	—	unknown	—	50.2° 11:50	10.08	64%	128.6°
2034-10-22 Sun	—	unknown	—	50.2° 11:45	10.12	74%	141.7°
2034-10-23 Mon	—	unknown	—	50.2° 11:40	10.16	83%	155.1°
2034-10-24 Tue	—	unknown	—	50.2° 11:35	10.2	90%	168.8°
2034-10-25 Wed	—	unknown	—	50.2° 11:35	10.24	96%	174.6°
2034-10-26 Thu	—	unknown	—	50.2° 11:30	10.28	99%	160.8°
2034-10-27 Fri	—	unknown	—	50.2° 11:25	10.32	100%	145.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-09-28&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.