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.

2034-05-06astronomy score per night — click a bar for that night2034-06-04

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-05-06 Sat	—	unknown	—	72.5° 14:10	6.07	90%	154.1°
2034-05-07 Sun	—	unknown	—	72.5° 14:10	6.02	83%	142.5°
2034-05-08 Mon	—	unknown	—	72.5° 14:05	5.96	75%	130.5°
2034-05-09 Tue	—	unknown	—	72.5° 14:00	5.9	66%	118.1°
2034-05-10 Wed	—	unknown	—	72.5° 13:55	5.85	56%	105.5°
2034-05-11 Thu	—	unknown	—	72.5° 13:50	5.79	45%	92.4°
2034-05-12 Fri	—	unknown	—	72.5° 13:50	5.74	34%	79.0°
2034-05-13 Sat	—	unknown	—	72.5° 13:45	5.68	24%	65.1°
2034-05-14 Sun	—	unknown	—	72.5° 13:40	5.63	15%	50.9°
2034-05-15 Mon	—	unknown	—	72.5° 13:35	5.57	7%	36.4°
2034-05-16 Tue	—	unknown	—	72.5° 13:35	5.52	2%	22.0°
2034-05-17 Wed	—	unknown	—	72.5° 13:30	5.47	0%	9.9°
2034-05-18 Thu	—	unknown	—	72.5° 13:25	5.42	1%	13.0°
2034-05-19 Fri	—	unknown	—	72.5° 13:20	5.37	5%	26.2°
2034-05-20 Sat	—	unknown	—	72.5° 13:15	5.32	11%	40.3°
2034-05-21 Sun	—	unknown	—	72.5° 13:15	5.27	20%	54.1°
2034-05-22 Mon	—	unknown	—	72.5° 13:10	5.22	29%	67.6°
2034-05-23 Tue	—	unknown	—	72.5° 13:05	5.17	39%	80.7°
2034-05-24 Wed	—	unknown	—	72.5° 13:00	5.13	49%	93.4°
2034-05-25 Thu	—	unknown	—	72.5° 12:55	5.08	59%	105.7°
2034-05-26 Fri	—	unknown	—	72.5° 12:55	5.04	69%	117.8°
2034-05-27 Sat	—	unknown	—	72.5° 12:50	4.99	77%	129.6°
2034-05-28 Sun	—	unknown	—	72.5° 12:45	4.95	85%	141.3°
2034-05-29 Mon	—	unknown	—	72.5° 12:40	4.91	91%	152.6°
2034-05-30 Tue	—	unknown	—	72.5° 12:40	4.87	95%	163.5°
2034-05-31 Wed	—	unknown	—	72.5° 12:35	4.83	98%	171.2°
2034-06-01 Thu	—	unknown	—	72.5° 12:30	4.79	100%	167.3°
2034-06-02 Fri	—	unknown	—	72.5° 12:25	4.76	99%	156.9°
2034-06-03 Sat	—	unknown	—	72.5° 12:20	4.72	97%	145.4°
2034-06-04 Sun	—	unknown	—	72.5° 12:20	4.69	93%	133.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-05-06&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.