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: 11-26 (100), 11-27 (100), 11-28 (100), 11-29 (100), 11-30 (100) — by astronomy; check the weather when the night is within four days.

2029-11-21astronomy score per night — click a bar for that night2029-12-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-11-21 Wed	26	—	unknown	19:05–21:30 (marginal, 2.42 h)	72.5° 00:05	11.13	100%	8.7°
2029-11-22 Thu	33	—	unknown	18:45–23:00 (marginal, 4.25 h)	72.5° 00:00	11.15	97%	20.6°
2029-11-23 Fri	53	—	unknown	18:35–01:30 (marginal, 6.92 h)	72.5° 23:55	11.17	93%	32.8°
2029-11-24 Sat	84	—	unknown	18:45–19:45 (good, 1.0 h)	72.5° 23:55	11.2	87%	45.1°
2029-11-25 Sun	92	—	unknown	18:45–00:40 (good, 5.92 h)	72.5° 23:50	11.22	80%	57.6°
2029-11-26 Mon	100	—	unknown	18:40–03:10 (good, 8.5 h)	72.5° 23:45	11.24	71%	70.3°
2029-11-27 Tue	100	—	unknown	18:35–04:25 (good, 9.83 h)	72.5° 23:40	11.26	61%	83.3°
2029-11-28 Wed	100	—	unknown	18:35–04:35 (good, 10.0 h)	72.5° 23:35	11.28	51%	96.7°
2029-11-29 Thu	100	—	unknown	18:35–04:40 (good, 10.08 h)	72.5° 23:35	11.3	40%	110.3°
2029-11-30 Fri	100	—	unknown	18:35–04:35 (good, 10.0 h)	72.5° 23:30	11.32	29%	124.4°
2029-12-01 Sat	100	—	unknown	18:35–04:35 (good, 10.0 h)	72.5° 23:25	11.34	19%	138.8°
2029-12-02 Sun	100	—	unknown	18:35–04:30 (good, 9.92 h)	72.5° 23:20	11.35	11%	153.6°
2029-12-03 Mon	100	—	unknown	18:35–04:30 (good, 9.92 h)	72.5° 23:15	11.37	4%	168.5°
2029-12-04 Tue	100	—	unknown	18:35–04:25 (good, 9.83 h)	72.5° 23:15	11.38	1%	175.9°
2029-12-05 Wed	100	—	unknown	18:35–04:20 (good, 9.75 h)	72.5° 23:10	11.4	0%	161.2°
2029-12-06 Thu	100	—	unknown	18:35–04:15 (good, 9.67 h)	72.5° 23:05	11.41	2%	146.4°
2029-12-07 Fri	100	—	unknown	18:35–04:10 (good, 9.58 h)	72.5° 23:00	11.42	7%	132.0°
2029-12-08 Sat	100	—	unknown	18:35–04:10 (good, 9.58 h)	72.5° 23:00	11.44	14%	117.9°
2029-12-09 Sun	100	—	unknown	18:35–04:05 (good, 9.5 h)	72.5° 22:55	11.45	23%	104.4°
2029-12-10 Mon	100	—	unknown	18:35–04:00 (good, 9.42 h)	72.5° 22:50	11.46	32%	91.3°
2029-12-11 Tue	100	—	unknown	18:35–03:55 (good, 9.33 h)	72.5° 22:45	11.47	42%	78.6°
2029-12-12 Wed	100	—	unknown	18:35–03:55 (good, 9.33 h)	72.5° 22:40	11.47	52%	66.3°
2029-12-13 Thu	94	—	unknown	19:35–03:50 (good, 8.25 h)	72.5° 22:40	11.48	61%	54.2°
2029-12-14 Fri	86	—	unknown	23:00–03:45 (good, 4.75 h)	72.5° 22:35	11.49	70%	42.3°
2029-12-15 Sat	70	—	unknown	03:25–03:40 (good, 0.25 h)	72.5° 22:30	11.49	79%	30.5°
2029-12-16 Sun	44	—	unknown	18:35–03:55 (marginal, 9.33 h)	72.5° 22:25	11.5	86%	18.7°
2029-12-17 Mon	31	—	unknown	22:55–03:35 (marginal, 4.67 h)	72.5° 22:20	11.5	92%	6.9°
2029-12-18 Tue	23	—	unknown	18:35–20:10 (marginal, 1.58 h)	72.5° 22:20	11.5	96%	5.6°
2029-12-19 Wed	23	—	unknown	18:35–20:35 (marginal, 2.0 h)	72.5° 22:15	11.51	99%	17.4°
2029-12-20 Thu	27	—	unknown	18:35–21:20 (marginal, 2.75 h)	72.5° 22:10	11.51	100%	29.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-11-21&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.