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: 11-12 (100), 11-13 (100), 11-14 (100), 11-15 (100), 11-16 (100) — by astronomy; check the weather when the night is within four days.

2042-11-12astronomy score per night — click a bar for that night2042-12-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2042-11-22 Sat	98	—	unknown	21:30–05:15 (good, 7.75 h)	72.5° 00:00	11.15	75%	59.2°
2042-11-23 Sun	88	—	unknown	01:35–05:10 (good, 3.58 h)	72.5° 00:00	11.17	84%	44.6°
2042-11-24 Mon	65	—	unknown	04:55–05:05 (good, 0.17 h)	72.6° 23:55	11.19	92%	29.8°
2042-11-25 Tue	33	—	unknown	01:05–05:05 (marginal, 4.0 h)	72.6° 23:50	11.22	97%	14.7°
2042-11-26 Wed	23	—	unknown	19:00–19:50 (marginal, 0.83 h)	72.5° 23:45	11.24	100%	0.7°
2042-11-27 Thu	27	—	unknown	18:40–21:40 (marginal, 3.0 h)	72.5° 23:40	11.26	99%	15.2°
2042-11-28 Fri	36	—	unknown	18:35–23:15 (marginal, 4.67 h)	72.5° 23:40	11.28	96%	29.9°
2042-11-29 Sat	74	—	unknown	18:35–18:50 (good, 0.25 h)	72.6° 23:35	11.3	90%	44.1°
2042-11-30 Sun	88	—	unknown	18:35–23:45 (good, 5.17 h)	72.6° 23:30	11.32	83%	57.9°
2042-12-01 Mon	98	—	unknown	18:35–02:40 (good, 8.08 h)	72.5° 23:25	11.33	74%	71.2°
2042-12-02 Tue	100	—	unknown	18:35–04:05 (good, 9.5 h)	72.5° 23:25	11.35	64%	84.1°
2042-12-03 Wed	100	—	unknown	18:35–04:15 (good, 9.67 h)	72.5° 23:20	11.37	55%	96.6°
2042-12-04 Thu	100	—	unknown	18:35–04:20 (good, 9.75 h)	72.6° 23:15	11.38	45%	108.9°
2042-12-05 Fri	100	—	unknown	18:35–04:20 (good, 9.75 h)	72.6° 23:10	11.4	36%	120.8°
2042-12-06 Sat	100	—	unknown	18:35–04:15 (good, 9.67 h)	72.5° 23:05	11.41	27%	132.7°
2042-12-07 Sun	100	—	unknown	18:35–04:10 (good, 9.58 h)	72.5° 23:05	11.42	19%	144.5°
2042-12-08 Mon	100	—	unknown	18:35–04:10 (good, 9.58 h)	72.6° 23:00	11.43	12%	156.4°
2042-12-09 Tue	100	—	unknown	18:35–04:05 (good, 9.5 h)	72.6° 22:55	11.44	7%	168.3°
2042-12-10 Wed	100	—	unknown	18:35–04:00 (good, 9.42 h)	72.5° 22:50	11.45	3%	179.3°
2042-12-11 Thu	100	—	unknown	18:35–04:00 (good, 9.42 h)	72.5° 22:45	11.46	1%	167.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-11-12&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.