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.

2036-05-14astronomy score per night — click a bar for that night2036-06-12

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-05-14 Wed	—	unknown	—	72.5° 13:40	5.6	80%	131.9°
2036-05-15 Thu	—	unknown	—	72.5° 13:35	5.55	72%	120.3°
2036-05-16 Fri	—	unknown	—	72.5° 13:30	5.49	63%	108.6°
2036-05-17 Sat	—	unknown	—	72.5° 13:25	5.44	54%	96.9°
2036-05-18 Sun	—	unknown	—	72.5° 13:25	5.39	45%	85.1°
2036-05-19 Mon	—	unknown	—	72.5° 13:20	5.34	35%	73.1°
2036-05-20 Tue	—	unknown	—	72.5° 13:15	5.29	26%	60.9°
2036-05-21 Wed	—	unknown	—	72.5° 13:10	5.24	18%	48.4°
2036-05-22 Thu	—	unknown	—	72.5° 13:05	5.19	10%	35.6°
2036-05-23 Fri	—	unknown	—	72.5° 13:05	5.15	5%	22.9°
2036-05-24 Sat	—	unknown	—	72.5° 13:00	5.1	1%	11.6°
2036-05-25 Sun	—	unknown	—	72.5° 12:55	5.06	0%	11.5°
2036-05-26 Mon	—	unknown	—	72.5° 12:50	5.01	2%	23.3°
2036-05-27 Tue	—	unknown	—	72.5° 12:45	4.97	6%	37.1°
2036-05-28 Wed	—	unknown	—	72.5° 12:45	4.93	13%	51.4°
2036-05-29 Thu	—	unknown	—	72.5° 12:40	4.89	22%	65.7°
2036-05-30 Fri	—	unknown	—	72.5° 12:35	4.85	33%	79.9°
2036-05-31 Sat	—	unknown	—	72.5° 12:30	4.81	44%	94.0°
2036-06-01 Sun	—	unknown	—	72.5° 12:30	4.78	55%	107.8°
2036-06-02 Mon	—	unknown	—	72.5° 12:25	4.74	66%	121.3°
2036-06-03 Tue	—	unknown	—	72.5° 12:20	4.71	76%	134.5°
2036-06-04 Wed	—	unknown	—	72.5° 12:15	4.68	84%	147.3°
2036-06-05 Thu	—	unknown	—	72.5° 12:10	4.65	91%	159.4°
2036-06-06 Fri	—	unknown	—	72.5° 12:10	4.62	96%	169.3°
2036-06-07 Sat	—	unknown	—	72.5° 12:00	4.59	99%	168.6°
2036-06-08 Sun	—	unknown	—	72.5° 12:00	4.57	100%	158.7°
2036-06-09 Mon	—	unknown	—	72.5° 11:50	4.54	99%	147.2°
2036-06-10 Tue	—	unknown	—	72.5° 11:50	4.52	96%	135.6°
2036-06-11 Wed	—	unknown	—	72.5° 11:45	4.5	91%	123.9°
2036-06-12 Thu	—	unknown	—	72.5° 11:40	4.49	85%	112.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-05-14&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.