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: 10-24 (100), 10-25 (100), 10-26 (100), 10-27 (100), 10-28 (100) — by astronomy; check the weather when the night is within four days.

2035-10-17astronomy score per night — click a bar for that night2035-11-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-10-17 Wed	26	—	unknown	03:40–06:05 (marginal, 2.42 h)	72.5° 03:25	9.9	99%	26.2°
2035-10-18 Thu	24	—	unknown	22:25–01:30 (marginal, 3.08 h)	72.5° 03:20	9.94	96%	13.9°
2035-10-19 Fri	32	—	unknown	22:05–06:10 (marginal, 8.08 h)	72.5° 03:15	9.98	90%	10.0°
2035-10-20 Sat	45	—	unknown	21:45–06:10 (marginal, 8.42 h)	72.5° 03:10	10.03	82%	20.4°
2035-10-21 Sun	71	—	unknown	22:05–22:20 (good, 0.25 h)	72.5° 03:10	10.07	72%	33.8°
2035-10-22 Mon	86	—	unknown	22:00–05:25 (good, 7.42 h)	72.5° 03:05	10.11	61%	47.7°
2035-10-23 Tue	95	—	unknown	21:55–06:15 (good, 8.33 h)	72.5° 03:00	10.15	50%	61.5°
2035-10-24 Wed	100	—	unknown	21:50–06:15 (good, 8.42 h)	72.5° 02:55	10.19	38%	75.3°
2035-10-25 Thu	100	—	unknown	21:45–06:15 (good, 8.5 h)	72.5° 02:55	10.23	28%	89.0°
2035-10-26 Fri	100	—	unknown	21:45–06:15 (good, 8.5 h)	72.5° 02:50	10.27	19%	102.4°
2035-10-27 Sat	100	—	unknown	21:40–05:15 (good, 8.58 h)	72.5° 02:45	10.31	11%	115.7°
2035-10-28 Sun	100	—	unknown	20:35–05:20 (good, 8.75 h)	72.5° 01:40	10.35	5%	128.8°
2035-10-29 Mon	100	—	unknown	20:30–05:20 (good, 8.83 h)	72.5° 01:35	10.38	2%	141.5°
2035-10-30 Tue	100	—	unknown	20:25–05:20 (good, 8.92 h)	72.5° 01:35	10.42	0%	153.7°
2035-10-31 Wed	100	—	unknown	20:25–05:20 (good, 8.92 h)	72.5° 01:30	10.46	1%	164.9°
2035-11-01 Thu	100	—	unknown	20:20–05:20 (good, 9.0 h)	72.5° 01:25	10.49	3%	170.9°
2035-11-02 Fri	100	—	unknown	20:15–05:25 (good, 9.17 h)	72.5° 01:20	10.53	8%	164.6°
2035-11-03 Sat	100	—	unknown	20:10–05:25 (good, 9.25 h)	72.5° 01:15	10.57	14%	153.9°
2035-11-04 Sun	100	—	unknown	20:10–05:25 (good, 9.25 h)	72.5° 01:15	10.6	21%	142.6°
2035-11-05 Mon	100	—	unknown	20:05–05:25 (good, 9.33 h)	72.5° 01:10	10.64	29%	131.1°
2035-11-06 Tue	100	—	unknown	20:05–05:30 (good, 9.42 h)	72.5° 01:05	10.67	38%	119.5°
2035-11-07 Wed	100	—	unknown	20:05–05:30 (good, 9.42 h)	72.5° 01:00	10.7	47%	107.8°
2035-11-08 Thu	100	—	unknown	20:05–05:30 (good, 9.42 h)	72.5° 01:00	10.74	56%	95.9°
2035-11-09 Fri	100	—	unknown	20:10–05:30 (good, 9.33 h)	72.5° 00:55	10.77	66%	83.7°
2035-11-10 Sat	100	—	unknown	21:10–05:30 (good, 8.33 h)	72.5° 00:50	10.8	75%	71.2°
2035-11-11 Sun	98	—	unknown	23:20–05:35 (good, 6.25 h)	72.5° 00:45	10.83	84%	58.4°
2035-11-12 Mon	89	—	unknown	02:50–05:35 (good, 2.75 h)	72.5° 00:40	10.86	91%	45.2°
2035-11-13 Tue	80	—	unknown	05:20–05:35 (good, 0.25 h)	72.5° 00:40	10.89	96%	31.8°
2035-11-14 Wed	34	—	unknown	01:40–05:35 (marginal, 3.92 h)	72.5° 00:35	10.92	99%	18.6°
2035-11-15 Thu	27	—	unknown	19:35–21:45 (marginal, 2.17 h)	72.5° 00:30	10.95	100%	9.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-10-17&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.