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.

2034-07-28astronomy score per night — click a bar for that night2034-08-26

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-07-28 Fri	—	unknown	—	50.2° 17:25	5.63	94%	92.2°
2034-07-29 Sat	—	unknown	—	50.2° 17:25	5.69	98%	104.8°
2034-07-30 Sun	—	unknown	—	50.2° 17:20	5.74	100%	117.6°
2034-07-31 Mon	—	unknown	—	50.2° 17:15	5.8	99%	130.7°
2034-08-01 Tue	—	unknown	—	50.2° 17:10	5.85	97%	144.1°
2034-08-02 Wed	—	unknown	—	50.2° 17:05	5.91	92%	157.6°
2034-08-03 Thu	—	unknown	—	50.2° 17:05	5.96	85%	170.9°
2034-08-04 Fri	—	unknown	—	50.2° 17:00	6.02	76%	173.3°
2034-08-05 Sat	—	unknown	—	50.2° 16:55	6.07	65%	160.0°
2034-08-06 Sun	—	unknown	—	50.2° 16:50	6.13	54%	146.1°
2034-08-07 Mon	—	unknown	—	50.2° 16:45	6.19	42%	131.9°
2034-08-08 Tue	—	unknown	—	50.2° 16:45	6.24	31%	117.8°
2034-08-09 Wed	—	unknown	—	50.2° 16:40	6.3	21%	103.6°
2034-08-10 Thu	—	unknown	—	50.2° 16:35	6.36	13%	89.5°
2034-08-11 Fri	—	unknown	—	50.2° 16:30	6.42	6%	75.5°
2034-08-12 Sat	—	unknown	—	50.2° 16:30	6.47	2%	61.7°
2034-08-13 Sun	—	unknown	—	50.2° 16:25	6.53	0%	48.1°
2034-08-14 Mon	—	unknown	—	50.2° 16:20	6.59	1%	34.8°
2034-08-15 Tue	—	unknown	—	50.2° 16:15	6.65	4%	21.8°
2034-08-16 Wed	—	unknown	—	50.2° 16:10	6.7	8%	9.5°
2034-08-17 Thu	—	unknown	—	50.2° 16:10	6.76	15%	5.3°
2034-08-18 Fri	—	unknown	—	50.2° 16:05	6.82	22%	16.4°
2034-08-19 Sat	—	unknown	—	50.2° 16:00	6.88	31%	28.2°
2034-08-20 Sun	—	unknown	—	50.2° 15:55	6.93	40%	40.0°
2034-08-21 Mon	—	unknown	—	50.2° 15:50	6.99	49%	51.8°
2034-08-22 Tue	—	unknown	—	50.2° 15:50	7.05	58%	63.6°
2034-08-23 Wed	—	unknown	—	50.2° 15:45	7.11	68%	75.6°
2034-08-24 Thu	—	unknown	—	50.2° 15:40	7.16	77%	87.8°
2034-08-25 Fri	—	unknown	—	50.2° 15:35	7.22	84%	100.2°
2034-08-26 Sat	—	unknown	—	50.2° 15:35	7.28	91%	112.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-07-28&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.