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.

2033-03-24astronomy score per night — click a bar for that night2033-04-22

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-03-24 Thu	—	unknown	—	89.6° 12:55	8.5	41%	97.6°
2033-03-25 Fri	—	unknown	—	89.5° 12:55	8.44	30%	86.1°
2033-03-26 Sat	—	unknown	—	89.7° 12:50	8.39	20%	74.4°
2033-03-27 Sun	—	unknown	—	89.8° 13:45	8.34	12%	62.7°
2033-03-28 Mon	—	unknown	—	89.7° 13:40	8.28	5%	51.6°
2033-03-29 Tue	—	unknown	—	89.6° 13:35	8.23	1%	41.9°
2033-03-30 Wed	—	unknown	—	89.6° 13:35	8.18	0%	35.4°
2033-03-31 Thu	—	unknown	—	89.7° 13:30	8.12	2%	34.0°
2033-04-01 Fri	—	unknown	—	89.8° 13:25	8.07	7%	38.2°
2033-04-02 Sat	—	unknown	—	89.7° 13:20	8.01	14%	46.0°
2033-04-03 Sun	—	unknown	—	89.5° 13:15	7.96	23%	55.7°
2033-04-04 Mon	—	unknown	—	89.6° 13:15	7.9	33%	66.1°
2033-04-05 Tue	—	unknown	—	89.7° 13:10	7.84	43%	76.7°
2033-04-06 Wed	—	unknown	—	89.7° 13:05	7.79	53%	87.1°
2033-04-07 Thu	—	unknown	—	89.6° 13:00	7.73	63%	97.4°
2033-04-08 Fri	—	unknown	—	89.5° 13:00	7.68	72%	107.3°
2033-04-09 Sat	—	unknown	—	89.7° 12:55	7.62	80%	116.9°
2033-04-10 Sun	—	unknown	—	89.8° 12:50	7.56	87%	125.9°
2033-04-11 Mon	—	unknown	—	89.7° 12:45	7.51	93%	134.0°
2033-04-12 Tue	—	unknown	—	89.6° 12:40	7.45	97%	140.6°
2033-04-13 Wed	—	unknown	—	89.6° 12:40	7.39	99%	145.0°
2033-04-14 Thu	—	unknown	—	89.7° 12:35	7.33	100%	146.1°
2033-04-15 Fri	—	unknown	—	89.8° 12:30	7.28	99%	143.6°
2033-04-16 Sat	—	unknown	—	89.7° 12:25	7.22	96%	138.0°
2033-04-17 Sun	—	unknown	—	89.5° 12:20	7.16	91%	130.2°
2033-04-18 Mon	—	unknown	—	89.6° 12:20	7.1	84%	121.1°
2033-04-19 Tue	—	unknown	—	89.7° 12:15	7.04	76%	111.1°
2033-04-20 Wed	—	unknown	—	89.7° 12:10	6.99	67%	100.5°
2033-04-21 Thu	—	unknown	—	89.6° 12:05	6.93	56%	89.4°
2033-04-22 Fri	—	unknown	—	89.7° 12:00	6.87	45%	78.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-03-24&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.