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.

2032-04-17astronomy score per night — click a bar for that night2032-05-16

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2032-04-17 Sat	—	unknown	—	72.5° 15:25	7.15	53%	62.5°
2032-04-18 Sun	—	unknown	—	72.5° 15:20	7.09	62%	74.2°
2032-04-19 Mon	—	unknown	—	72.5° 15:15	7.03	71%	86.0°
2032-04-20 Tue	—	unknown	—	72.5° 15:15	6.97	79%	97.9°
2032-04-21 Wed	—	unknown	—	72.5° 15:10	6.91	86%	109.9°
2032-04-22 Thu	—	unknown	—	72.5° 15:05	6.86	92%	122.0°
2032-04-23 Fri	—	unknown	—	72.5° 15:00	6.8	97%	134.4°
2032-04-24 Sat	—	unknown	—	72.5° 14:55	6.74	100%	147.0°
2032-04-25 Sun	—	unknown	—	72.5° 14:55	6.68	100%	159.7°
2032-04-26 Mon	—	unknown	—	72.5° 14:50	6.62	98%	171.4°
2032-04-27 Tue	—	unknown	—	72.5° 14:45	6.56	94%	170.6°
2032-04-28 Wed	—	unknown	—	72.5° 14:40	6.51	88%	158.2°
2032-04-29 Thu	—	unknown	—	72.5° 14:35	6.45	79%	144.7°
2032-04-30 Fri	—	unknown	—	72.5° 14:35	6.39	69%	130.8°
2032-05-01 Sat	—	unknown	—	72.5° 14:30	6.33	58%	116.9°
2032-05-02 Sun	—	unknown	—	72.5° 14:25	6.27	47%	102.8°
2032-05-03 Mon	—	unknown	—	72.5° 14:20	6.22	36%	88.7°
2032-05-04 Tue	—	unknown	—	72.5° 14:20	6.16	25%	74.5°
2032-05-05 Wed	—	unknown	—	72.5° 14:15	6.1	16%	60.5°
2032-05-06 Thu	—	unknown	—	72.5° 14:10	6.04	8%	46.5°
2032-05-07 Fri	—	unknown	—	72.5° 14:05	5.99	3%	32.7°
2032-05-08 Sat	—	unknown	—	72.5° 14:00	5.93	0%	19.4°
2032-05-09 Sun	—	unknown	—	72.5° 14:00	5.88	0%	7.7°
2032-05-10 Mon	—	unknown	—	72.5° 13:55	5.82	2%	10.2°
2032-05-11 Tue	—	unknown	—	72.5° 13:50	5.76	6%	22.0°
2032-05-12 Wed	—	unknown	—	72.5° 13:45	5.71	12%	34.2°
2032-05-13 Thu	—	unknown	—	72.5° 13:40	5.66	19%	46.4°
2032-05-14 Fri	—	unknown	—	72.5° 13:40	5.6	27%	58.4°
2032-05-15 Sat	—	unknown	—	72.5° 13:35	5.55	36%	70.3°
2032-05-16 Sun	—	unknown	—	72.5° 13:30	5.5	46%	82.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2032-04-17&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.