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), 07-16 (2), 07-17 (2), 07-07 (1), 07-08 (1) — by astronomy; check the weather when the night is within four days.

2033-06-18astronomy score per night — click a bar for that night2033-07-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-06-18 Sat	0	—	unknown	—	72.6° 11:20	4.43	62%	75.5°
2033-06-19 Sun	0	—	unknown	—	72.6° 11:15	4.42	51%	61.5°
2033-06-20 Mon	0	—	unknown	—	72.6° 11:10	4.42	39%	47.5°
2033-06-21 Tue	0	—	unknown	—	72.6° 11:05	4.42	28%	33.5°
2033-06-22 Wed	0	—	unknown	—	72.6° 11:00	4.43	19%	20.0°
2033-06-23 Thu	0	—	unknown	—	72.6° 11:00	4.43	11%	8.7°
2033-06-24 Fri	0	—	unknown	—	72.6° 10:55	4.44	5%	12.1°
2033-06-25 Sat	0	—	unknown	—	72.6° 10:50	4.45	1%	24.4°
2033-06-26 Sun	0	—	unknown	—	72.6° 10:45	4.46	0%	37.5°
2033-06-27 Mon	0	—	unknown	—	72.6° 10:45	4.47	2%	50.6°
2033-06-28 Tue	0	—	unknown	—	72.6° 10:40	4.49	5%	63.4°
2033-06-29 Wed	0	—	unknown	—	72.6° 10:35	4.5	10%	76.0°
2033-06-30 Thu	0	—	unknown	—	72.6° 10:30	4.52	17%	88.3°
2033-07-01 Fri	0	—	unknown	—	72.6° 10:25	4.54	25%	100.3°
2033-07-02 Sat	0	—	unknown	—	72.6° 10:25	4.57	33%	112.2°
2033-07-03 Sun	0	—	unknown	—	72.6° 10:20	4.59	43%	124.0°
2033-07-04 Mon	0	—	unknown	—	72.6° 10:15	4.62	52%	135.6°
2033-07-05 Tue	0	—	unknown	—	72.6° 10:10	4.65	62%	147.3°
2033-07-06 Wed	0	—	unknown	—	72.6° 10:05	4.68	71%	158.8°
2033-07-07 Thu	1	—	unknown	—	72.6° 10:05	4.71	79%	169.3°
2033-07-08 Fri	1	—	unknown	—	72.6° 10:00	4.74	87%	171.0°
2033-07-09 Sat	1	—	unknown	—	72.6° 09:55	4.78	93%	160.7°
2033-07-10 Sun	1	—	unknown	—	72.6° 09:50	4.81	97%	148.2°
2033-07-11 Mon	1	—	unknown	—	72.6° 09:50	4.85	100%	134.9°
2033-07-12 Tue	2	—	unknown	—	72.6° 09:45	4.89	99%	121.3°
2033-07-13 Wed	1	—	unknown	—	72.6° 09:40	4.93	97%	107.3°
2033-07-14 Thu	1	—	unknown	—	72.6° 09:35	4.97	92%	93.2°
2033-07-15 Fri	1	—	unknown	—	72.6° 09:30	5.01	84%	79.0°
2033-07-16 Sat	2	—	unknown	—	72.6° 09:30	5.06	75%	64.7°
2033-07-17 Sun	2	—	unknown	04:00–04:05 (marginal, 0.08 h)	72.6° 09:25	5.1	64%	50.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-06-18&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.