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.

2038-10-01astronomy score per night — click a bar for that night2038-10-30

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-10-01 Fri	—	unknown	—	50.1° 13:10	9.18	14%	46.9°
2038-10-02 Sat	—	unknown	—	50.1° 13:05	9.23	23%	61.6°
2038-10-03 Sun	—	unknown	—	50.1° 13:05	9.28	34%	75.9°
2038-10-04 Mon	—	unknown	—	50.1° 13:00	9.33	45%	89.8°
2038-10-05 Tue	—	unknown	—	50.1° 12:55	9.37	56%	103.3°
2038-10-06 Wed	—	unknown	—	50.1° 12:50	9.42	66%	116.5°
2038-10-07 Thu	—	unknown	—	50.1° 12:50	9.47	75%	129.4°
2038-10-08 Fri	—	unknown	—	50.1° 12:45	9.51	83%	142.1°
2038-10-09 Sat	—	unknown	—	50.1° 12:40	9.56	90%	154.5°
2038-10-10 Sun	—	unknown	—	50.1° 12:35	9.6	95%	166.8°
2038-10-11 Mon	—	unknown	—	50.1° 12:30	9.65	98%	178.9°
2038-10-12 Tue	—	unknown	—	50.1° 12:30	9.69	100%	169.1°
2038-10-13 Wed	—	unknown	—	50.1° 12:25	9.74	99%	157.2°
2038-10-14 Thu	—	unknown	—	50.1° 12:20	9.78	97%	145.3°
2038-10-15 Fri	—	unknown	—	50.1° 12:15	9.82	93%	133.5°
2038-10-16 Sat	—	unknown	—	50.1° 12:10	9.87	88%	121.7°
2038-10-17 Sun	—	unknown	—	50.1° 12:10	9.91	81%	109.8°
2038-10-18 Mon	—	unknown	—	50.1° 12:00	9.95	73%	97.8°
2038-10-19 Tue	—	unknown	—	50.1° 12:00	10.0	64%	85.6°
2038-10-20 Wed	—	unknown	—	50.1° 11:50	10.04	54%	73.2°
2038-10-21 Thu	—	unknown	—	50.1° 11:50	10.08	44%	60.4°
2038-10-22 Fri	—	unknown	—	50.1° 11:45	10.12	34%	47.2°
2038-10-23 Sat	—	unknown	—	50.1° 11:40	10.16	24%	33.6°
2038-10-24 Sun	—	unknown	—	50.1° 11:35	10.2	15%	19.5°
2038-10-25 Mon	—	unknown	—	50.1° 11:35	10.24	8%	5.0°
2038-10-26 Tue	—	unknown	—	50.1° 11:30	10.28	3%	10.0°
2038-10-27 Wed	—	unknown	—	50.1° 11:25	10.32	0%	25.1°
2038-10-28 Thu	—	unknown	—	50.1° 11:20	10.36	1%	40.4°
2038-10-29 Fri	—	unknown	—	50.1° 11:15	10.39	5%	55.6°
2038-10-30 Sat	—	unknown	—	50.1° 10:15	10.43	11%	70.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-10-01&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.