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: 11-18 (100), 11-19 (100), 11-20 (100), 11-21 (100), 11-22 (100) — by astronomy; check the weather when the night is within four days.

2038-11-09astronomy score per night — click a bar for that night2038-12-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-11-09 Tue	82	—	unknown	05:15–05:30 (good, 0.25 h)	72.5° 00:55	10.78	96%	35.1°
2038-11-10 Wed	37	—	unknown	01:15–05:30 (marginal, 4.25 h)	72.5° 00:50	10.81	99%	23.6°
2038-11-11 Thu	29	—	unknown	02:35–05:35 (marginal, 3.0 h)	72.5° 00:45	10.84	100%	12.8°
2038-11-12 Fri	27	—	unknown	19:40–22:05 (marginal, 2.42 h)	72.5° 00:40	10.87	99%	6.9°
2038-11-13 Sat	32	—	unknown	19:25–23:25 (marginal, 4.0 h)	72.5° 00:35	10.9	96%	14.6°
2038-11-14 Sun	41	—	unknown	19:10–01:05 (marginal, 5.92 h)	72.5° 00:35	10.93	92%	25.8°
2038-11-15 Mon	70	—	unknown	19:25–19:40 (good, 0.25 h)	72.5° 00:30	10.96	86%	37.5°
2038-11-16 Tue	85	—	unknown	19:20–23:40 (good, 4.33 h)	72.5° 00:25	10.99	79%	49.6°
2038-11-17 Wed	93	—	unknown	19:15–03:00 (good, 7.75 h)	72.5° 00:20	11.02	70%	62.0°
2038-11-18 Thu	100	—	unknown	19:10–04:40 (good, 9.5 h)	72.5° 00:20	11.04	60%	74.6°
2038-11-19 Fri	100	—	unknown	19:10–05:05 (good, 9.92 h)	72.5° 00:15	11.07	50%	87.6°
2038-11-20 Sat	100	—	unknown	19:05–05:10 (good, 10.08 h)	72.5° 00:10	11.1	39%	100.9°
2038-11-21 Sun	100	—	unknown	19:00–05:15 (good, 10.25 h)	72.5° 00:05	11.12	29%	114.7°
2038-11-22 Mon	100	—	unknown	18:55–05:10 (good, 10.25 h)	72.5° 00:00	11.15	19%	128.9°
2038-11-23 Tue	100	—	unknown	18:50–05:10 (good, 10.33 h)	72.5° 00:00	11.17	10%	143.4°
2038-11-24 Wed	100	—	unknown	18:50–05:05 (good, 10.25 h)	72.5° 23:55	11.19	4%	157.9°
2038-11-25 Thu	100	—	unknown	18:45–05:00 (good, 10.25 h)	72.5° 23:50	11.21	1%	171.0°
2038-11-26 Fri	100	—	unknown	18:40–04:55 (good, 10.25 h)	72.5° 23:45	11.24	0%	168.4°
2038-11-27 Sat	100	—	unknown	18:35–04:55 (good, 10.33 h)	72.5° 23:40	11.26	3%	154.7°
2038-11-28 Sun	100	—	unknown	18:35–04:50 (good, 10.25 h)	72.5° 23:40	11.28	8%	140.3°
2038-11-29 Mon	100	—	unknown	18:35–04:45 (good, 10.17 h)	72.5° 23:35	11.3	15%	126.2°
2038-11-30 Tue	100	—	unknown	18:35–04:40 (good, 10.08 h)	72.5° 23:30	11.31	24%	112.4°
2038-12-01 Wed	100	—	unknown	18:35–04:35 (good, 10.0 h)	72.5° 23:25	11.33	34%	99.2°
2038-12-02 Thu	100	—	unknown	18:35–04:35 (good, 10.0 h)	72.5° 23:20	11.35	44%	86.4°
2038-12-03 Fri	100	—	unknown	18:35–04:30 (good, 9.92 h)	72.5° 23:20	11.37	54%	73.9°
2038-12-04 Sat	100	—	unknown	19:25–04:25 (good, 9.0 h)	72.5° 23:15	11.38	64%	61.8°
2038-12-05 Sun	93	—	unknown	21:30–04:20 (good, 6.83 h)	72.5° 23:10	11.39	72%	49.9°
2038-12-06 Mon	85	—	unknown	03:10–04:20 (good, 1.17 h)	72.5° 23:05	11.41	80%	38.1°
2038-12-07 Tue	65	—	unknown	04:05–04:15 (good, 0.17 h)	72.5° 23:05	11.42	87%	26.6°
2038-12-08 Wed	38	—	unknown	18:35–04:20 (marginal, 9.75 h)	72.5° 23:00	11.43	93%	15.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-11-09&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.