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.

2039-11-12astronomy score per night — click a bar for that night2039-12-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-11-12 Sat	100	—	unknown	19:35–05:35 (good, 10.0 h)	72.5° 00:40	10.87	15%	125.2°
2039-11-13 Sun	100	—	unknown	19:30–05:35 (good, 10.08 h)	72.5° 00:40	10.9	8%	139.1°
2039-11-14 Mon	100	—	unknown	19:30–05:35 (good, 10.08 h)	72.5° 00:35	10.93	3%	153.3°
2039-11-15 Tue	100	—	unknown	19:25–05:35 (good, 10.17 h)	72.5° 00:30	10.95	0%	167.5°
2039-11-16 Wed	100	—	unknown	19:20–05:35 (good, 10.25 h)	72.5° 00:25	10.98	1%	173.5°
2039-11-17 Thu	100	—	unknown	19:15–05:35 (good, 10.33 h)	72.5° 00:20	11.01	4%	160.5°
2039-11-18 Fri	100	—	unknown	19:15–05:30 (good, 10.25 h)	72.5° 00:20	11.04	10%	145.8°
2039-11-19 Sat	100	—	unknown	19:10–05:25 (good, 10.25 h)	72.5° 00:15	11.06	19%	131.2°
2039-11-20 Sun	100	—	unknown	19:10–05:20 (good, 10.17 h)	72.5° 00:10	11.09	29%	116.8°
2039-11-21 Mon	100	—	unknown	19:10–05:20 (good, 10.17 h)	72.5° 00:05	11.12	39%	102.8°
2039-11-22 Tue	100	—	unknown	19:10–05:15 (good, 10.08 h)	72.5° 00:05	11.14	50%	89.2°
2039-11-23 Wed	100	—	unknown	19:15–05:10 (good, 9.92 h)	72.5° 00:00	11.16	61%	76.0°
2039-11-24 Thu	100	—	unknown	20:35–05:05 (good, 8.5 h)	72.5° 23:55	11.19	71%	63.0°
2039-11-25 Fri	93	—	unknown	23:40–05:00 (good, 5.33 h)	72.5° 23:50	11.21	80%	50.4°
2039-11-26 Sat	85	—	unknown	03:50–05:00 (good, 1.17 h)	72.5° 23:45	11.23	87%	38.0°
2039-11-27 Sun	57	—	unknown	18:55–05:20 (marginal, 10.42 h)	72.5° 23:45	11.25	93%	25.9°
2039-11-28 Mon	34	—	unknown	00:45–04:55 (marginal, 4.17 h)	72.5° 23:40	11.27	97%	14.2°
2039-11-29 Tue	26	—	unknown	18:40–20:25 (marginal, 1.75 h)	72.5° 23:35	11.29	99%	5.4°
2039-11-30 Wed	27	—	unknown	18:35–21:20 (marginal, 2.75 h)	72.5° 23:30	11.31	100%	12.0°
2039-12-01 Thu	32	—	unknown	18:35–22:20 (marginal, 3.75 h)	72.5° 23:25	11.33	99%	23.2°
2039-12-02 Fri	45	—	unknown	18:35–00:35 (marginal, 6.0 h)	72.5° 23:25	11.35	96%	34.8°
2039-12-03 Sat	82	—	unknown	18:35–19:00 (good, 0.42 h)	72.5° 23:20	11.36	91%	46.6°
2039-12-04 Sun	89	—	unknown	18:35–23:20 (good, 4.75 h)	72.5° 23:15	11.38	85%	58.4°
2039-12-05 Mon	97	—	unknown	18:35–02:05 (good, 7.5 h)	72.5° 23:10	11.39	77%	70.2°
2039-12-06 Tue	100	—	unknown	18:35–03:30 (good, 8.92 h)	72.5° 23:10	11.41	69%	82.3°
2039-12-07 Wed	100	—	unknown	18:35–03:55 (good, 9.33 h)	72.5° 23:05	11.42	59%	94.6°
2039-12-08 Thu	100	—	unknown	18:35–04:00 (good, 9.42 h)	72.5° 23:00	11.43	49%	107.1°
2039-12-09 Fri	100	—	unknown	18:35–04:05 (good, 9.5 h)	72.5° 22:55	11.44	39%	120.0°
2039-12-10 Sat	100	—	unknown	18:35–04:00 (good, 9.42 h)	72.5° 22:50	11.45	29%	133.3°
2039-12-11 Sun	100	—	unknown	18:35–04:00 (good, 9.42 h)	72.5° 22:50	11.46	19%	147.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-11-12&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.