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: 11-30 (100), 12-01 (100), 12-02 (100), 12-03 (100), 12-04 (100) — by astronomy; check the weather when the night is within four days.

2038-11-30astronomy score per night — click a bar for that night2038-12-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2038-12-09 Thu	27	—	unknown	01:05–04:00 (marginal, 2.92 h)	72.5° 22:55	11.44	97%	7.2°
2038-12-10 Fri	26	—	unknown	18:35–20:55 (marginal, 2.33 h)	72.5° 22:50	11.45	99%	12.0°
2038-12-11 Sat	28	—	unknown	18:35–21:30 (marginal, 2.92 h)	72.5° 22:45	11.46	100%	22.9°
2038-12-12 Sun	38	—	unknown	18:35–23:10 (marginal, 4.58 h)	72.5° 22:45	11.47	99%	34.7°
2038-12-13 Mon	56	—	unknown	18:35–03:25 (marginal, 8.83 h)	72.5° 22:40	11.48	96%	46.8°
2038-12-14 Tue	90	—	unknown	18:35–22:15 (good, 3.67 h)	72.5° 22:35	11.49	90%	59.1°
2038-12-15 Wed	98	—	unknown	18:35–01:10 (good, 6.58 h)	72.5° 22:30	11.49	84%	71.7°
2038-12-16 Thu	100	—	unknown	18:35–02:45 (good, 8.17 h)	72.5° 22:25	11.5	75%	84.5°
2038-12-17 Fri	100	—	unknown	18:35–03:15 (good, 8.67 h)	72.5° 22:25	11.5	66%	97.5°
2038-12-18 Sat	100	—	unknown	18:35–03:20 (good, 8.75 h)	72.5° 22:20	11.5	55%	110.9°
2038-12-19 Sun	100	—	unknown	18:35–03:20 (good, 8.75 h)	72.5° 22:15	11.51	44%	124.5°
2038-12-20 Mon	100	—	unknown	18:35–03:20 (good, 8.75 h)	72.5° 22:10	11.51	33%	138.3°
2038-12-21 Tue	100	—	unknown	18:35–03:15 (good, 8.67 h)	72.5° 22:10	11.51	23%	152.4°
2038-12-22 Wed	100	—	unknown	18:35–03:15 (good, 8.67 h)	72.5° 22:05	11.51	14%	166.1°
2038-12-23 Thu	100	—	unknown	18:40–03:10 (good, 8.5 h)	72.5° 22:00	11.51	6%	172.6°
2038-12-24 Fri	100	—	unknown	18:40–03:05 (good, 8.42 h)	72.5° 21:55	11.5	2%	161.1°
2038-12-25 Sat	100	—	unknown	18:40–03:05 (good, 8.42 h)	72.5° 21:50	11.5	0%	146.9°
2038-12-26 Sun	100	—	unknown	18:40–03:00 (good, 8.33 h)	72.5° 21:50	11.5	1%	132.5°
2038-12-27 Mon	100	—	unknown	18:40–02:55 (good, 8.25 h)	72.5° 21:45	11.49	5%	118.3°
2038-12-28 Tue	100	—	unknown	18:40–02:50 (good, 8.17 h)	72.5° 21:40	11.48	11%	104.5°
2038-12-29 Wed	100	—	unknown	18:40–02:45 (good, 8.08 h)	72.5° 21:35	11.48	18%	91.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-11-30&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.