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: 08-29 (96), 08-30 (96), 08-31 (96), 08-28 (93), 08-27 (91) — by astronomy; check the weather when the night is within four days.

2047-08-09astronomy score per night — click a bar for that night2047-09-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-08-09 Fri	13	—	unknown	02:45–04:40 (marginal, 1.92 h)	72.6° 07:55	6.29	83%	54.2°
2047-08-10 Sat	13	—	unknown	02:40–04:40 (marginal, 2.0 h)	72.6° 07:50	6.35	75%	42.1°
2047-08-11 Sun	13	—	unknown	02:35–04:40 (marginal, 2.08 h)	72.6° 07:50	6.41	67%	30.1°
2047-08-12 Mon	19	—	unknown	02:20–04:45 (marginal, 2.42 h)	72.6° 07:45	6.47	57%	18.3°
2047-08-13 Tue	25	—	unknown	04:25–04:45 (good, 0.33 h)	72.6° 07:40	6.52	48%	6.4°
2047-08-14 Wed	33	—	unknown	02:55–04:45 (good, 1.83 h)	72.6° 07:35	6.58	39%	5.5°
2047-08-15 Thu	41	—	unknown	02:40–04:45 (good, 2.08 h)	72.6° 07:30	6.64	30%	17.6°
2047-08-16 Fri	51	—	unknown	02:30–04:50 (good, 2.33 h)	72.6° 07:30	6.7	21%	29.9°
2047-08-17 Sat	60	—	unknown	02:20–04:50 (good, 2.5 h)	72.6° 07:25	6.75	13%	42.5°
2047-08-18 Sun	66	—	unknown	02:15–04:50 (good, 2.58 h)	72.6° 07:20	6.81	7%	55.5°
2047-08-19 Mon	71	—	unknown	02:10–04:55 (good, 2.75 h)	72.6° 07:15	6.87	3%	68.8°
2047-08-20 Tue	74	—	unknown	02:05–04:55 (good, 2.83 h)	72.6° 07:15	6.93	0%	82.5°
2047-08-21 Wed	76	—	unknown	02:05–04:55 (good, 2.83 h)	72.6° 07:10	6.98	0%	96.5°
2047-08-22 Thu	80	—	unknown	02:00–05:00 (good, 3.0 h)	72.6° 07:05	7.04	3%	110.7°
2047-08-23 Fri	82	—	unknown	01:55–05:00 (good, 3.08 h)	72.6° 07:00	7.1	9%	125.0°
2047-08-24 Sat	84	—	unknown	01:50–05:00 (good, 3.17 h)	72.6° 06:55	7.15	16%	139.5°
2047-08-25 Sun	86	—	unknown	01:45–05:00 (good, 3.25 h)	72.6° 06:55	7.21	26%	153.9°
2047-08-26 Mon	89	—	unknown	01:45–05:05 (good, 3.33 h)	72.6° 06:50	7.27	36%	168.2°
2047-08-27 Tue	91	—	unknown	01:40–05:05 (good, 3.42 h)	72.6° 06:45	7.33	48%	177.5°
2047-08-28 Wed	93	—	unknown	01:35–05:05 (good, 3.5 h)	72.6° 06:40	7.38	59%	163.5°
2047-08-29 Thu	96	—	unknown	01:30–05:10 (good, 3.67 h)	72.6° 06:35	7.44	70%	149.7°
2047-08-30 Fri	96	—	unknown	01:35–05:10 (good, 3.58 h)	72.6° 06:35	7.49	80%	136.0°
2047-08-31 Sat	96	—	unknown	01:30–05:10 (good, 3.67 h)	72.6° 06:30	7.55	88%	122.5°
2047-09-01 Sun	91	—	unknown	01:35–05:10 (good, 3.58 h)	72.6° 06:25	7.61	94%	109.2°
2047-09-02 Mon	68	—	unknown	01:40–05:15 (good, 3.58 h)	72.6° 06:20	7.66	98%	96.2°
2047-09-03 Tue	53	—	unknown	02:55–05:15 (good, 2.33 h)	72.6° 06:20	7.72	100%	83.3°
2047-09-04 Wed	40	—	unknown	04:20–05:15 (good, 0.92 h)	72.6° 06:15	7.77	100%	70.7°
2047-09-05 Thu	29	—	unknown	01:05–05:15 (marginal, 4.17 h)	72.6° 06:10	7.83	97%	58.3°
2047-09-06 Fri	21	—	unknown	01:10–05:20 (marginal, 4.17 h)	72.6° 06:05	7.88	93%	46.1°
2047-09-07 Sat	16	—	unknown	01:15–05:20 (marginal, 4.08 h)	72.6° 06:00	7.94	88%	34.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-08-09&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.