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.

2036-07-26astronomy score per night — click a bar for that night2036-08-24

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-07-26 Sat	—	unknown	—	50.2° 17:35	5.56	17%	12.4°
2036-07-27 Sun	—	unknown	—	50.2° 17:30	5.61	27%	2.1°
2036-07-28 Mon	—	unknown	—	50.2° 17:25	5.66	37%	15.7°
2036-07-29 Tue	—	unknown	—	50.2° 17:20	5.72	48%	29.1°
2036-07-30 Wed	—	unknown	—	50.2° 17:15	5.77	58%	42.1°
2036-07-31 Thu	—	unknown	—	50.2° 17:15	5.82	68%	54.7°
2036-08-01 Fri	—	unknown	—	50.2° 17:10	5.88	77%	67.1°
2036-08-02 Sat	—	unknown	—	50.2° 17:05	5.94	85%	79.3°
2036-08-03 Sun	—	unknown	—	50.2° 17:00	5.99	91%	91.3°
2036-08-04 Mon	—	unknown	—	50.2° 16:55	6.05	96%	103.3°
2036-08-05 Tue	—	unknown	—	50.2° 16:55	6.1	99%	115.1°
2036-08-06 Wed	—	unknown	—	50.2° 16:50	6.16	100%	127.0°
2036-08-07 Thu	—	unknown	—	50.2° 16:45	6.22	99%	138.8°
2036-08-08 Fri	—	unknown	—	50.2° 16:40	6.27	97%	150.7°
2036-08-09 Sat	—	unknown	—	50.2° 16:35	6.33	93%	162.6°
2036-08-10 Sun	—	unknown	—	50.2° 16:35	6.39	87%	174.7°
2036-08-11 Mon	—	unknown	—	50.2° 16:30	6.45	80%	173.0°
2036-08-12 Tue	—	unknown	—	50.2° 16:25	6.5	71%	160.6°
2036-08-13 Wed	—	unknown	—	50.2° 16:20	6.56	62%	148.0°
2036-08-14 Thu	—	unknown	—	50.2° 16:20	6.62	51%	135.0°
2036-08-15 Fri	—	unknown	—	50.2° 16:15	6.68	41%	121.6°
2036-08-16 Sat	—	unknown	—	50.2° 16:10	6.73	30%	107.8°
2036-08-17 Sun	—	unknown	—	50.2° 16:05	6.79	20%	93.6°
2036-08-18 Mon	—	unknown	—	50.2° 16:00	6.85	11%	79.0°
2036-08-19 Tue	—	unknown	—	50.2° 16:00	6.91	5%	64.1°
2036-08-20 Wed	—	unknown	—	50.2° 15:55	6.96	1%	48.9°
2036-08-21 Thu	—	unknown	—	50.2° 15:50	7.02	0%	33.7°
2036-08-22 Fri	—	unknown	—	50.2° 15:45	7.08	2%	18.7°
2036-08-23 Sat	—	unknown	—	50.2° 15:40	7.13	7%	3.9°
2036-08-24 Sun	—	unknown	—	50.2° 15:40	7.19	14%	10.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-07-26&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.