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: 10-27 (100), 10-28 (100), 11-09 (100), 11-10 (100), 11-11 (100) — by astronomy; check the weather when the night is within four days.

2028-10-27astronomy score per night — click a bar for that night2028-11-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-10-27 Fri	100	—	unknown	22:05–06:20 (good, 8.25 h)	72.5° 02:40	10.33	75%	84.6°
2028-10-28 Sat	100	—	unknown	23:25–05:20 (good, 6.92 h)	72.5° 02:40	10.37	82%	72.8°
2028-10-29 Sun	97	—	unknown	00:40–05:20 (good, 4.67 h)	72.5° 01:35	10.41	89%	61.0°
2028-10-30 Mon	89	—	unknown	03:25–05:20 (good, 1.92 h)	72.5° 01:30	10.45	94%	49.1°
2028-10-31 Tue	46	—	unknown	22:55–05:20 (marginal, 6.42 h)	72.5° 01:25	10.48	98%	37.1°
2028-11-01 Wed	30	—	unknown	02:15–05:25 (marginal, 3.17 h)	72.5° 01:20	10.52	100%	25.0°
2028-11-02 Thu	24	—	unknown	03:20–05:25 (marginal, 2.08 h)	72.5° 01:20	10.56	100%	12.7°
2028-11-03 Fri	23	—	unknown	20:25–21:55 (marginal, 1.5 h)	72.5° 01:15	10.59	98%	0.5°
2028-11-04 Sat	31	—	unknown	20:00–00:10 (marginal, 4.17 h)	72.5° 01:10	10.63	94%	12.5°
2028-11-05 Sun	43	—	unknown	19:45–04:00 (marginal, 8.25 h)	72.5° 01:05	10.66	88%	25.3°
2028-11-06 Mon	72	—	unknown	19:55–20:15 (good, 0.33 h)	72.5° 01:00	10.69	80%	38.3°
2028-11-07 Tue	87	—	unknown	19:55–01:55 (good, 6.0 h)	72.5° 01:00	10.73	71%	51.6°
2028-11-08 Wed	96	—	unknown	19:50–04:40 (good, 8.83 h)	72.5° 00:55	10.76	61%	65.1°
2028-11-09 Thu	100	—	unknown	19:45–05:30 (good, 9.75 h)	72.5° 00:50	10.79	50%	78.9°
2028-11-10 Fri	100	—	unknown	19:40–05:35 (good, 9.92 h)	72.5° 00:45	10.82	38%	92.9°
2028-11-11 Sat	100	—	unknown	19:35–05:35 (good, 10.0 h)	72.5° 00:45	10.86	28%	107.2°
2028-11-12 Sun	100	—	unknown	19:35–05:35 (good, 10.0 h)	72.5° 00:40	10.89	18%	121.7°
2028-11-13 Mon	100	—	unknown	19:30–05:35 (good, 10.08 h)	72.5° 00:35	10.92	10%	136.4°
2028-11-14 Tue	100	—	unknown	19:25–05:35 (good, 10.17 h)	72.5° 00:30	10.95	4%	151.1°
2028-11-15 Wed	100	—	unknown	19:20–05:40 (good, 10.33 h)	72.5° 00:25	10.97	1%	165.8°
2028-11-16 Thu	100	—	unknown	19:15–05:35 (good, 10.33 h)	72.5° 00:25	11.0	0%	179.5°
2028-11-17 Fri	100	—	unknown	19:15–05:30 (good, 10.25 h)	72.5° 00:20	11.03	2%	165.6°
2028-11-18 Sat	100	—	unknown	19:10–05:25 (good, 10.25 h)	72.5° 00:15	11.06	7%	151.7°
2028-11-19 Sun	100	—	unknown	19:05–05:20 (good, 10.25 h)	72.5° 00:10	11.08	14%	138.3°
2028-11-20 Mon	100	—	unknown	19:05–05:20 (good, 10.25 h)	72.5° 00:05	11.11	21%	125.3°
2028-11-21 Tue	100	—	unknown	19:00–05:15 (good, 10.25 h)	72.5° 00:05	11.13	30%	112.7°
2028-11-22 Wed	100	—	unknown	19:00–05:10 (good, 10.17 h)	72.5° 00:00	11.16	40%	100.4°
2028-11-23 Thu	100	—	unknown	19:05–05:05 (good, 10.0 h)	72.5° 23:55	11.18	49%	88.3°
2028-11-24 Fri	100	—	unknown	19:10–05:00 (good, 9.83 h)	72.5° 23:50	11.2	59%	76.4°
2028-11-25 Sat	100	—	unknown	20:20–05:00 (good, 8.67 h)	72.5° 23:50	11.22	68%	64.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-10-27&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.