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: 10-10 (100), 10-11 (100), 10-12 (100), 10-13 (100), 10-14 (100) — by astronomy; check the weather when the night is within four days.

2031-10-01astronomy score per night — click a bar for that night2031-10-30

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-10-01 Wed	25	—	unknown	02:00–05:50 (marginal, 3.83 h)	72.5° 04:25	9.17	98%	36.7°
2031-10-02 Thu	19	—	unknown	04:15–05:50 (marginal, 1.58 h)	72.5° 04:25	9.22	95%	23.4°
2031-10-03 Fri	22	—	unknown	23:20–05:50 (marginal, 6.5 h)	72.5° 04:20	9.27	89%	11.0°
2031-10-04 Sat	32	—	unknown	23:00–05:50 (marginal, 6.83 h)	72.5° 04:15	9.31	82%	5.8°
2031-10-05 Sun	44	—	unknown	22:45–05:55 (marginal, 7.17 h)	72.5° 04:10	9.36	73%	16.1°
2031-10-06 Mon	59	—	unknown	22:35–05:55 (marginal, 7.33 h)	72.5° 04:05	9.41	64%	27.9°
2031-10-07 Tue	82	—	unknown	23:00–05:55 (good, 6.92 h)	72.5° 04:05	9.45	55%	39.7°
2031-10-08 Wed	90	—	unknown	22:55–05:55 (good, 7.0 h)	72.5° 04:00	9.5	46%	51.5°
2031-10-09 Thu	97	—	unknown	22:50–05:55 (good, 7.08 h)	72.5° 03:55	9.54	36%	63.2°
2031-10-10 Fri	100	—	unknown	22:45–06:00 (good, 7.25 h)	72.5° 03:50	9.59	27%	75.1°
2031-10-11 Sat	100	—	unknown	22:40–06:00 (good, 7.33 h)	72.5° 03:50	9.64	19%	87.1°
2031-10-12 Sun	100	—	unknown	22:40–06:00 (good, 7.33 h)	72.5° 03:45	9.68	12%	99.3°
2031-10-13 Mon	100	—	unknown	22:35–06:00 (good, 7.42 h)	72.5° 03:40	9.72	6%	111.7°
2031-10-14 Tue	100	—	unknown	22:30–06:05 (good, 7.58 h)	72.5° 03:35	9.77	2%	124.4°
2031-10-15 Wed	100	—	unknown	22:25–06:05 (good, 7.67 h)	72.5° 03:30	9.81	0%	137.4°
2031-10-16 Thu	100	—	unknown	22:20–06:05 (good, 7.75 h)	72.5° 03:30	9.86	0%	150.6°
2031-10-17 Fri	100	—	unknown	22:20–06:05 (good, 7.75 h)	72.5° 03:25	9.9	3%	163.9°
2031-10-18 Sat	100	—	unknown	22:15–06:05 (good, 7.83 h)	72.5° 03:20	9.94	8%	174.7°
2031-10-19 Sun	100	—	unknown	22:10–06:10 (good, 8.0 h)	72.5° 03:15	9.98	15%	166.6°
2031-10-20 Mon	100	—	unknown	22:05–06:10 (good, 8.08 h)	72.5° 03:10	10.02	24%	153.0°
2031-10-21 Tue	100	—	unknown	22:05–06:10 (good, 8.08 h)	72.5° 03:10	10.07	34%	139.1°
2031-10-22 Wed	100	—	unknown	22:05–06:10 (good, 8.08 h)	72.5° 03:05	10.11	46%	125.0°
2031-10-23 Thu	100	—	unknown	22:05–06:15 (good, 8.17 h)	72.5° 03:00	10.15	57%	110.9°
2031-10-24 Fri	100	—	unknown	22:10–06:15 (good, 8.08 h)	72.5° 02:55	10.19	68%	96.9°
2031-10-25 Sat	100	—	unknown	22:35–05:15 (good, 7.67 h)	72.5° 02:55	10.23	78%	82.9°
2031-10-26 Sun	100	—	unknown	23:15–05:15 (good, 6.0 h)	72.5° 01:50	10.27	87%	69.0°
2031-10-27 Mon	94	—	unknown	02:30–05:15 (good, 2.75 h)	72.5° 01:45	10.31	93%	55.2°
2031-10-28 Tue	54	—	unknown	21:00–05:20 (marginal, 8.33 h)	72.5° 01:40	10.34	98%	41.7°
2031-10-29 Wed	31	—	unknown	02:05–05:20 (marginal, 3.25 h)	72.5° 01:35	10.38	100%	28.4°
2031-10-30 Thu	25	—	unknown	03:10–05:20 (marginal, 2.17 h)	72.5° 01:35	10.42	100%	15.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-10-01&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.