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: 08-31 (100), 09-01 (100), 09-02 (100), 09-03 (100), 09-04 (100) — by astronomy; check the weather when the night is within four days.

2046-08-06astronomy score per night — click a bar for that night2046-09-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-08-06 Mon	41	—	unknown	03:00–04:35 (good, 1.58 h)	72.6° 08:05	6.14	27%	137.0°
2046-08-07 Tue	43	—	unknown	02:55–04:35 (good, 1.67 h)	72.6° 08:05	6.19	37%	151.3°
2046-08-08 Wed	45	—	unknown	02:55–04:35 (good, 1.67 h)	72.6° 08:00	6.25	49%	165.3°
2046-08-09 Thu	48	—	unknown	02:50–04:40 (good, 1.83 h)	72.6° 07:55	6.31	60%	178.8°
2046-08-10 Fri	50	—	unknown	02:45–04:40 (good, 1.92 h)	72.6° 07:50	6.36	70%	167.6°
2046-08-11 Sat	51	—	unknown	02:40–04:40 (good, 2.0 h)	72.6° 07:45	6.42	79%	154.4°
2046-08-12 Sun	55	—	unknown	02:45–04:45 (good, 2.0 h)	72.6° 07:45	6.48	87%	141.5°
2046-08-13 Mon	55	—	unknown	02:40–04:45 (good, 2.08 h)	72.6° 07:40	6.54	93%	128.8°
2046-08-14 Tue	48	—	unknown	02:40–04:45 (good, 2.08 h)	72.6° 07:35	6.59	97%	116.3°
2046-08-15 Wed	42	—	unknown	02:45–04:50 (good, 2.08 h)	72.6° 07:30	6.65	100%	104.0°
2046-08-16 Thu	36	—	unknown	03:15–04:50 (good, 1.58 h)	72.6° 07:25	6.71	100%	91.9°
2046-08-17 Fri	29	—	unknown	04:20–04:50 (good, 0.5 h)	72.6° 07:25	6.77	98%	79.8°
2046-08-18 Sat	23	—	unknown	02:05–04:50 (marginal, 2.75 h)	72.6° 07:20	6.82	95%	67.9°
2046-08-19 Sun	19	—	unknown	02:05–04:55 (marginal, 2.83 h)	72.6° 07:15	6.88	90%	56.1°
2046-08-20 Mon	16	—	unknown	02:05–04:55 (marginal, 2.83 h)	72.6° 07:10	6.94	84%	44.3°
2046-08-21 Tue	15	—	unknown	02:00–04:55 (marginal, 2.92 h)	72.6° 07:10	7.0	76%	32.4°
2046-08-22 Wed	20	—	unknown	01:50–05:00 (marginal, 3.17 h)	72.6° 07:05	7.05	68%	20.5°
2046-08-23 Thu	27	—	unknown	01:35–05:00 (marginal, 3.42 h)	72.6° 07:00	7.11	58%	8.4°
2046-08-24 Fri	38	—	unknown	03:15–05:00 (good, 1.75 h)	72.6° 06:55	7.17	48%	4.0°
2046-08-25 Sat	49	—	unknown	02:05–05:05 (good, 3.0 h)	72.6° 06:50	7.23	38%	16.6°
2046-08-26 Sun	62	—	unknown	01:55–05:05 (good, 3.17 h)	72.6° 06:50	7.28	28%	29.7°
2046-08-27 Mon	77	—	unknown	01:40–05:05 (good, 3.42 h)	72.6° 06:45	7.34	19%	43.2°
2046-08-28 Tue	89	—	unknown	01:35–05:05 (good, 3.5 h)	72.6° 06:40	7.4	11%	57.1°
2046-08-29 Wed	96	—	unknown	01:30–05:10 (good, 3.67 h)	72.6° 06:35	7.45	5%	71.6°
2046-08-30 Thu	98	—	unknown	01:25–05:10 (good, 3.75 h)	72.6° 06:30	7.51	1%	86.4°
2046-08-31 Fri	100	—	unknown	01:20–05:10 (good, 3.83 h)	72.6° 06:30	7.56	0%	101.4°
2046-09-01 Sat	100	—	unknown	01:20–05:10 (good, 3.83 h)	72.6° 06:25	7.62	2%	116.6°
2046-09-02 Sun	100	—	unknown	01:15–05:15 (good, 4.0 h)	72.6° 06:20	7.68	7%	131.7°
2046-09-03 Mon	100	—	unknown	01:10–05:15 (good, 4.08 h)	72.6° 06:15	7.73	15%	146.6°
2046-09-04 Tue	100	—	unknown	01:05–05:15 (good, 4.17 h)	72.6° 06:15	7.79	24%	161.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-08-06&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.