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.

2036-04-28astronomy score per night — click a bar for that night2036-05-27

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-04-28 Mon	—	unknown	—	72.5° 14:40	6.5	8%	15.1°
2036-04-29 Tue	—	unknown	—	72.5° 14:40	6.45	15%	27.8°
2036-04-30 Wed	—	unknown	—	72.5° 14:35	6.39	25%	41.4°
2036-05-01 Thu	—	unknown	—	72.5° 14:30	6.33	35%	55.3°
2036-05-02 Fri	—	unknown	—	72.5° 14:25	6.27	46%	69.3°
2036-05-03 Sat	—	unknown	—	72.5° 14:20	6.21	58%	83.2°
2036-05-04 Sun	—	unknown	—	72.5° 14:20	6.16	69%	97.1°
2036-05-05 Mon	—	unknown	—	72.5° 14:15	6.1	78%	110.8°
2036-05-06 Tue	—	unknown	—	72.5° 14:10	6.04	87%	124.4°
2036-05-07 Wed	—	unknown	—	72.5° 14:05	5.99	93%	137.7°
2036-05-08 Thu	—	unknown	—	72.5° 14:00	5.93	98%	150.6°
2036-05-09 Fri	—	unknown	—	72.5° 14:00	5.87	100%	162.6°
2036-05-10 Sat	—	unknown	—	72.5° 13:55	5.82	99%	170.7°
2036-05-11 Sun	—	unknown	—	72.5° 13:50	5.76	97%	166.0°
2036-05-12 Mon	—	unknown	—	72.5° 13:45	5.71	93%	155.2°
2036-05-13 Tue	—	unknown	—	72.5° 13:45	5.65	87%	143.6°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-04-28&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.