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: 10-23 (100), 10-24 (100), 10-25 (100), 11-04 (100), 11-05 (100) — by astronomy; check the weather when the night is within four days.

2042-10-23astronomy score per night — click a bar for that night2042-11-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-10-23 Thu	100	—	unknown	22:10–06:15 (good, 8.08 h)	72.6° 03:00	10.16	69%	96.9°
2042-10-24 Fri	100	—	unknown	22:25–06:15 (good, 7.83 h)	72.5° 02:55	10.2	79%	82.8°
2042-10-25 Sat	100	—	unknown	00:15–05:15 (good, 6.0 h)	72.5° 02:50	10.24	88%	68.3°
2042-10-26 Sun	93	—	unknown	02:50–05:15 (good, 2.42 h)	72.5° 01:50	10.28	94%	53.4°
2042-10-27 Mon	46	—	unknown	22:05–05:15 (marginal, 7.17 h)	72.6° 01:45	10.32	99%	38.2°
2042-10-28 Tue	27	—	unknown	02:45–05:20 (marginal, 2.58 h)	72.6° 01:40	10.36	100%	22.9°
2042-10-29 Wed	22	—	unknown	04:00–05:20 (marginal, 1.33 h)	72.5° 01:35	10.4	98%	7.7°
2042-10-30 Thu	27	—	unknown	20:30–00:10 (marginal, 3.67 h)	72.5° 01:30	10.43	93%	7.3°
2042-10-31 Fri	40	—	unknown	20:10–05:20 (marginal, 9.17 h)	72.5° 01:30	10.47	86%	21.9°
2042-11-01 Sat	55	—	unknown	19:50–05:25 (marginal, 9.58 h)	72.6° 01:25	10.51	78%	36.0°
2042-11-02 Sun	83	—	unknown	20:15–02:15 (good, 6.0 h)	72.6° 01:20	10.54	68%	49.7°
2042-11-03 Mon	92	—	unknown	20:10–05:00 (good, 8.83 h)	72.5° 01:15	10.58	58%	62.9°
2042-11-04 Tue	100	—	unknown	20:05–05:25 (good, 9.33 h)	72.5° 01:15	10.61	47%	75.6°
2042-11-05 Wed	100	—	unknown	20:05–05:25 (good, 9.33 h)	72.5° 01:10	10.65	38%	88.1°
2042-11-06 Thu	100	—	unknown	20:00–05:30 (good, 9.5 h)	72.6° 01:05	10.68	28%	100.3°
2042-11-07 Fri	100	—	unknown	19:55–05:30 (good, 9.58 h)	72.6° 01:00	10.71	20%	112.3°
2042-11-08 Sat	100	—	unknown	19:50–05:30 (good, 9.67 h)	72.5° 00:55	10.75	13%	124.1°
2042-11-09 Sun	100	—	unknown	19:45–05:30 (good, 9.75 h)	72.5° 00:55	10.78	8%	136.0°
2042-11-10 Mon	100	—	unknown	19:45–05:30 (good, 9.75 h)	72.6° 00:50	10.81	3%	147.8°
2042-11-11 Tue	100	—	unknown	19:40–05:35 (good, 9.92 h)	72.6° 00:45	10.84	1%	159.6°
2042-11-12 Wed	100	—	unknown	19:35–05:35 (good, 10.0 h)	72.5° 00:40	10.87	0%	171.6°
2042-11-13 Thu	100	—	unknown	19:30–05:35 (good, 10.08 h)	72.5° 00:35	10.9	1%	176.4°
2042-11-14 Fri	100	—	unknown	19:25–05:35 (good, 10.17 h)	72.5° 00:35	10.93	4%	164.3°
2042-11-15 Sat	100	—	unknown	19:25–05:35 (good, 10.17 h)	72.6° 00:30	10.96	9%	152.0°
2042-11-16 Sun	100	—	unknown	19:20–05:35 (good, 10.25 h)	72.6° 00:25	10.99	15%	139.5°
2042-11-17 Mon	100	—	unknown	19:15–05:30 (good, 10.25 h)	72.5° 00:20	11.02	23%	126.9°
2042-11-18 Tue	100	—	unknown	19:15–05:30 (good, 10.25 h)	72.5° 00:20	11.05	32%	114.0°
2042-11-19 Wed	100	—	unknown	19:15–05:25 (good, 10.17 h)	72.5° 00:15	11.07	43%	100.8°
2042-11-20 Thu	100	—	unknown	19:20–05:20 (good, 10.0 h)	72.6° 00:10	11.1	54%	87.3°
2042-11-21 Fri	100	—	unknown	19:35–05:15 (good, 9.67 h)	72.6° 00:05	11.12	64%	73.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-10-23&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.