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.

Best nights for Seven Sisters: 07-12 (2), 07-10 (1), 07-11 (1) — by astronomy; check the weather when the night is within four days.

2034-06-13astronomy score per night — click a bar for that night2034-07-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-06-13 Tue	0	—	unknown	—	72.5° 11:40	4.48	9%	14.2°
2034-06-14 Wed	0	—	unknown	—	72.5° 11:35	4.47	4%	9.2°
2034-06-15 Thu	0	—	unknown	—	72.5° 11:30	4.45	1%	20.2°
2034-06-16 Fri	0	—	unknown	—	72.5° 11:25	4.44	0%	34.2°
2034-06-17 Sat	0	—	unknown	—	72.5° 11:25	4.43	3%	48.3°
2034-06-18 Sun	0	—	unknown	—	72.5° 11:20	4.43	9%	62.3°
2034-06-19 Mon	0	—	unknown	—	72.5° 11:15	4.42	16%	75.9°
2034-06-20 Tue	0	—	unknown	—	72.5° 11:10	4.42	24%	89.0°
2034-06-21 Wed	0	—	unknown	—	72.5° 11:05	4.42	34%	101.8°
2034-06-22 Thu	0	—	unknown	—	72.5° 11:05	4.43	43%	114.1°
2034-06-23 Fri	0	—	unknown	—	72.5° 11:00	4.43	53%	126.2°
2034-06-24 Sat	0	—	unknown	—	72.5° 10:55	4.44	63%	138.0°
2034-06-25 Sun	0	—	unknown	—	72.5° 10:50	4.45	72%	149.5°
2034-06-26 Mon	0	—	unknown	—	72.5° 10:45	4.46	80%	160.5°
2034-06-27 Tue	0	—	unknown	—	72.5° 10:45	4.47	87%	169.7°
2034-06-28 Wed	0	—	unknown	—	72.5° 10:40	4.48	92%	169.5°
2034-06-29 Thu	0	—	unknown	—	72.5° 10:35	4.5	97%	159.9°
2034-06-30 Fri	0	—	unknown	—	72.5° 10:30	4.52	99%	148.5°
2034-07-01 Sat	0	—	unknown	—	72.5° 10:30	4.54	100%	136.5°
2034-07-02 Sun	0	—	unknown	—	72.5° 10:25	4.56	98%	124.1°
2034-07-03 Mon	0	—	unknown	—	72.5° 10:20	4.59	95%	111.5°
2034-07-04 Tue	0	—	unknown	—	72.5° 10:15	4.61	89%	98.7°
2034-07-05 Wed	0	—	unknown	—	72.5° 10:10	4.64	82%	85.6°
2034-07-06 Thu	0	—	unknown	—	72.5° 10:10	4.67	73%	72.3°
2034-07-07 Fri	0	—	unknown	—	72.5° 10:05	4.7	63%	58.8°
2034-07-08 Sat	0	—	unknown	—	72.5° 10:00	4.73	52%	45.2°
2034-07-09 Sun	0	—	unknown	—	72.5° 09:55	4.77	40%	31.5°
2034-07-10 Mon	1	—	unknown	—	72.5° 09:50	4.8	29%	18.2°
2034-07-11 Tue	1	—	unknown	—	72.5° 09:50	4.84	19%	8.8°
2034-07-12 Wed	2	—	unknown	—	72.5° 09:45	4.88	11%	15.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-06-13&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.