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: 10-06 (100), 10-07 (100), 10-18 (100), 10-19 (100), 10-20 (100) — by astronomy; check the weather when the night is within four days.

2041-10-06astronomy score per night — click a bar for that night2041-11-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-10-06 Sun	100	—	unknown	23:45–05:55 (good, 6.17 h)	72.5° 04:05	9.43	88%	85.8°
2041-10-07 Mon	100	—	unknown	01:35–05:55 (good, 4.33 h)	72.5° 04:00	9.48	95%	70.8°
2041-10-08 Tue	63	—	unknown	04:55–05:55 (good, 1.0 h)	72.5° 04:00	9.53	99%	55.8°
2041-10-09 Wed	37	—	unknown	23:10–06:00 (marginal, 6.83 h)	72.5° 03:55	9.57	100%	40.8°
2041-10-10 Thu	22	—	unknown	04:15–06:00 (marginal, 1.75 h)	72.5° 03:50	9.62	98%	26.0°
2041-10-11 Fri	21	—	unknown	22:55–01:15 (marginal, 2.33 h)	72.5° 03:45	9.66	94%	11.6°
2041-10-12 Sat	28	—	unknown	22:30–06:00 (marginal, 7.5 h)	72.5° 03:40	9.71	87%	3.3°
2041-10-13 Sun	41	—	unknown	22:15–06:00 (marginal, 7.75 h)	72.5° 03:40	9.75	78%	16.3°
2041-10-14 Mon	56	—	unknown	22:05–06:05 (marginal, 8.0 h)	72.5° 03:35	9.79	69%	29.4°
2041-10-15 Tue	77	—	unknown	22:25–04:50 (good, 6.42 h)	72.5° 03:30	9.84	60%	42.1°
2041-10-16 Wed	87	—	unknown	22:20–06:05 (good, 7.75 h)	72.5° 03:25	9.88	50%	54.5°
2041-10-17 Thu	95	—	unknown	22:15–06:05 (good, 7.83 h)	72.5° 03:20	9.92	40%	66.6°
2041-10-18 Fri	100	—	unknown	22:15–06:10 (good, 7.92 h)	72.5° 03:20	9.97	31%	78.5°
2041-10-19 Sat	100	—	unknown	22:10–06:10 (good, 8.0 h)	72.5° 03:15	10.01	22%	90.3°
2041-10-20 Sun	100	—	unknown	22:05–06:10 (good, 8.08 h)	72.5° 03:10	10.05	15%	102.1°
2041-10-21 Mon	100	—	unknown	22:00–06:10 (good, 8.17 h)	72.5° 03:05	10.09	9%	114.0°
2041-10-22 Tue	100	—	unknown	21:55–06:10 (good, 8.25 h)	72.5° 03:05	10.13	4%	125.9°
2041-10-23 Wed	100	—	unknown	21:55–06:15 (good, 8.33 h)	72.5° 03:00	10.17	1%	138.0°
2041-10-24 Thu	100	—	unknown	21:50–06:15 (good, 8.42 h)	72.5° 02:55	10.21	0%	150.2°
2041-10-25 Fri	100	—	unknown	21:45–06:15 (good, 8.5 h)	72.5° 02:50	10.25	1%	162.5°
2041-10-26 Sat	100	—	unknown	21:40–05:15 (good, 8.58 h)	72.5° 02:45	10.29	3%	174.8°
2041-10-27 Sun	100	—	unknown	20:35–05:15 (good, 8.67 h)	72.5° 01:45	10.33	8%	171.7°
2041-10-28 Mon	100	—	unknown	20:35–05:20 (good, 8.75 h)	72.5° 01:40	10.37	15%	158.9°
2041-10-29 Tue	100	—	unknown	20:30–05:20 (good, 8.83 h)	72.5° 01:35	10.4	23%	145.7°
2041-10-30 Wed	100	—	unknown	20:30–05:20 (good, 8.83 h)	72.5° 01:30	10.44	33%	132.3°
2041-10-31 Thu	100	—	unknown	20:25–05:20 (good, 8.92 h)	72.5° 01:25	10.48	44%	118.6°
2041-11-01 Fri	100	—	unknown	20:25–05:25 (good, 9.0 h)	72.5° 01:25	10.51	55%	104.7°
2041-11-02 Sat	100	—	unknown	20:30–05:25 (good, 8.92 h)	72.5° 01:20	10.55	66%	90.6°
2041-11-03 Sun	100	—	unknown	21:10–05:25 (good, 8.25 h)	72.5° 01:15	10.59	76%	76.2°
2041-11-04 Mon	99	—	unknown	23:10–05:25 (good, 6.25 h)	72.5° 01:10	10.62	86%	61.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-10-06&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.