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: 11-14 (100), 11-15 (100), 11-16 (100), 11-17 (100), 11-18 (100) — by astronomy; check the weather when the night is within four days.

2041-11-05astronomy score per night — click a bar for that night2041-12-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-11-05 Tue	89	—	unknown	03:05–05:25 (good, 2.33 h)	72.5° 01:10	10.66	93%	47.0°
2041-11-06 Wed	44	—	unknown	23:50–05:30 (marginal, 5.67 h)	72.5° 01:05	10.69	98%	32.4°
2041-11-07 Thu	30	—	unknown	02:25–05:30 (marginal, 3.08 h)	72.5° 01:00	10.72	100%	17.9°
2041-11-08 Fri	23	—	unknown	04:15–05:30 (marginal, 1.25 h)	72.5° 00:55	10.76	99%	4.1°
2041-11-09 Sat	28	—	unknown	19:45–23:10 (marginal, 3.42 h)	72.5° 00:50	10.79	96%	10.6°
2041-11-10 Sun	39	—	unknown	19:30–01:20 (marginal, 5.83 h)	72.5° 00:50	10.82	91%	24.1°
2041-11-11 Mon	56	—	unknown	19:10–05:35 (marginal, 10.42 h)	72.5° 00:45	10.85	84%	37.3°
2041-11-12 Tue	84	—	unknown	19:35–00:20 (good, 4.75 h)	72.5° 00:40	10.88	76%	50.0°
2041-11-13 Wed	92	—	unknown	19:30–03:35 (good, 8.08 h)	72.5° 00:35	10.91	67%	62.5°
2041-11-14 Thu	100	—	unknown	19:25–05:05 (good, 9.67 h)	72.5° 00:30	10.94	57%	74.6°
2041-11-15 Fri	100	—	unknown	19:25–05:20 (good, 9.92 h)	72.5° 00:30	10.97	48%	86.6°
2041-11-16 Sat	100	—	unknown	19:20–05:25 (good, 10.08 h)	72.5° 00:25	11.0	38%	98.4°
2041-11-17 Sun	100	—	unknown	19:15–05:25 (good, 10.17 h)	72.5° 00:20	11.03	29%	110.2°
2041-11-18 Mon	100	—	unknown	19:10–05:25 (good, 10.25 h)	72.5° 00:15	11.05	21%	122.1°
2041-11-19 Tue	100	—	unknown	19:05–05:20 (good, 10.25 h)	72.5° 00:15	11.08	14%	134.1°
2041-11-20 Wed	100	—	unknown	19:05–05:20 (good, 10.25 h)	72.5° 00:10	11.1	8%	146.3°
2041-11-21 Thu	100	—	unknown	19:00–05:15 (good, 10.25 h)	72.5° 00:05	11.13	3%	158.7°
2041-11-22 Fri	100	—	unknown	18:55–05:10 (good, 10.25 h)	72.5° 00:00	11.15	1%	171.2°
2041-11-23 Sat	100	—	unknown	18:50–05:10 (good, 10.33 h)	72.5° 23:55	11.18	0%	175.2°
2041-11-24 Sun	100	—	unknown	18:45–05:05 (good, 10.33 h)	72.5° 23:55	11.2	2%	162.4°
2041-11-25 Mon	100	—	unknown	18:45–05:00 (good, 10.25 h)	72.5° 23:50	11.22	6%	149.0°
2041-11-26 Tue	100	—	unknown	18:40–04:55 (good, 10.25 h)	72.5° 23:45	11.24	12%	135.4°
2041-11-27 Wed	100	—	unknown	18:35–04:50 (good, 10.25 h)	72.5° 23:40	11.26	20%	121.7°
2041-11-28 Thu	100	—	unknown	18:35–04:50 (good, 10.25 h)	72.5° 23:35	11.28	29%	107.8°
2041-11-29 Fri	100	—	unknown	18:35–04:45 (good, 10.17 h)	72.5° 23:35	11.3	40%	93.8°
2041-11-30 Sat	100	—	unknown	18:40–04:40 (good, 10.0 h)	72.5° 23:30	11.32	51%	79.8°
2041-12-01 Sun	100	—	unknown	19:15–04:35 (good, 9.33 h)	72.5° 23:25	11.34	62%	65.6°
2041-12-02 Mon	93	—	unknown	21:35–04:30 (good, 6.92 h)	72.5° 23:20	11.35	73%	51.4°
2041-12-03 Tue	84	—	unknown	03:30–04:30 (good, 1.0 h)	72.5° 23:20	11.37	83%	37.2°
2041-12-04 Wed	46	—	unknown	18:35–04:40 (marginal, 10.08 h)	72.5° 23:15	11.38	90%	23.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-11-05&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.