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: 09-27 (100), 09-28 (100), 09-29 (100), 09-30 (100), 10-01 (100) — by astronomy; check the weather when the night is within four days.

2046-09-27astronomy score per night — click a bar for that night2046-10-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-09-27 Thu	100	—	unknown	23:35–05:45 (good, 6.17 h)	72.6° 04:40	8.99	7%	94.5°
2046-09-28 Fri	100	—	unknown	23:30–05:45 (good, 6.25 h)	72.6° 04:40	9.04	2%	109.5°
2046-09-29 Sat	100	—	unknown	23:30–05:45 (good, 6.25 h)	72.6° 04:35	9.09	0%	124.8°
2046-09-30 Sun	100	—	unknown	23:25–05:50 (good, 6.42 h)	72.6° 04:30	9.14	1%	140.1°
2046-10-01 Mon	100	—	unknown	23:20–05:50 (good, 6.5 h)	72.6° 04:25	9.19	5%	155.2°
2046-10-02 Tue	100	—	unknown	23:15–05:50 (good, 6.58 h)	72.6° 04:25	9.24	12%	170.0°
2046-10-03 Wed	100	—	unknown	23:15–05:50 (good, 6.58 h)	72.6° 04:20	9.28	20%	175.6°
2046-10-04 Thu	100	—	unknown	23:10–05:50 (good, 6.67 h)	72.6° 04:15	9.33	30%	161.7°
2046-10-05 Fri	100	—	unknown	23:05–05:55 (good, 6.83 h)	72.6° 04:10	9.38	40%	148.2°
2046-10-06 Sat	100	—	unknown	23:05–05:55 (good, 6.83 h)	72.6° 04:05	9.42	51%	135.2°
2046-10-07 Sun	100	—	unknown	23:00–05:55 (good, 6.92 h)	72.6° 04:05	9.47	61%	122.5°
2046-10-08 Mon	100	—	unknown	23:05–05:55 (good, 6.83 h)	72.6° 04:00	9.52	70%	110.2°
2046-10-09 Tue	100	—	unknown	23:10–06:00 (good, 6.83 h)	72.6° 03:55	9.56	78%	98.0°
2046-10-10 Wed	100	—	unknown	23:35–06:00 (good, 6.42 h)	72.6° 03:50	9.61	86%	86.1°
2046-10-11 Thu	100	—	unknown	01:00–06:00 (good, 5.0 h)	72.6° 03:45	9.65	92%	74.2°
2046-10-12 Fri	98	—	unknown	03:20–06:00 (good, 2.67 h)	72.6° 03:45	9.7	96%	62.3°
2046-10-13 Sat	55	—	unknown	05:40–06:00 (good, 0.33 h)	72.6° 03:40	9.74	99%	50.5°
2046-10-14 Sun	35	—	unknown	01:10–06:05 (marginal, 4.92 h)	72.6° 03:35	9.78	100%	38.6°
2046-10-15 Mon	22	—	unknown	04:10–06:05 (marginal, 1.92 h)	72.6° 03:30	9.83	99%	26.7°
2046-10-16 Tue	20	—	unknown	04:45–06:05 (marginal, 1.33 h)	72.6° 03:25	9.87	96%	14.7°
2046-10-17 Wed	23	—	unknown	22:25–01:45 (marginal, 3.33 h)	72.6° 03:25	9.91	92%	2.6°
2046-10-18 Thu	32	—	unknown	22:05–06:10 (marginal, 8.08 h)	72.6° 03:20	9.96	86%	9.7°
2046-10-19 Fri	46	—	unknown	21:50–06:10 (marginal, 8.33 h)	72.6° 03:15	10.0	78%	22.1°
2046-10-20 Sat	59	—	unknown	21:40–06:10 (marginal, 8.5 h)	72.6° 03:10	10.04	70%	34.8°
2046-10-21 Sun	85	—	unknown	22:00–05:30 (good, 7.5 h)	72.6° 03:10	10.08	60%	47.7°
2046-10-22 Mon	93	—	unknown	22:00–06:10 (good, 8.17 h)	72.6° 03:05	10.12	49%	61.0°
2046-10-23 Tue	100	—	unknown	21:55–06:15 (good, 8.33 h)	72.6° 03:00	10.16	38%	74.7°
2046-10-24 Wed	100	—	unknown	21:50–06:15 (good, 8.42 h)	72.6° 02:55	10.2	28%	88.7°
2046-10-25 Thu	100	—	unknown	21:45–06:15 (good, 8.5 h)	72.6° 02:50	10.24	18%	103.2°
2046-10-26 Fri	100	—	unknown	21:40–06:15 (good, 8.58 h)	72.6° 02:50	10.28	10%	118.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-09-27&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.