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: 08-12 (55), 08-13 (55), 08-11 (51), 08-10 (50), 08-09 (48) — by astronomy; check the weather when the night is within four days.

2046-07-25astronomy score per night — click a bar for that night2046-08-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-07-25 Wed	8	—	unknown	03:30–04:15 (marginal, 0.75 h)	72.6° 08:55	5.48	52%	28.8°
2046-07-26 Thu	11	—	unknown	03:15–04:15 (marginal, 1.0 h)	72.6° 08:50	5.53	42%	16.7°
2046-07-27 Fri	14	—	unknown	04:00–04:20 (good, 0.33 h)	72.6° 08:45	5.59	33%	4.3°
2046-07-28 Sat	18	—	unknown	03:50–04:20 (good, 0.5 h)	72.6° 08:40	5.64	23%	8.5°
2046-07-29 Sun	22	—	unknown	03:40–04:20 (good, 0.67 h)	72.6° 08:40	5.69	15%	21.6°
2046-07-30 Mon	26	—	unknown	03:30–04:25 (good, 0.92 h)	72.6° 08:35	5.75	8%	35.1°
2046-07-31 Tue	30	—	unknown	03:25–04:25 (good, 1.0 h)	72.6° 08:30	5.8	3%	49.1°
2046-08-01 Wed	31	—	unknown	03:20–04:25 (good, 1.08 h)	72.6° 08:25	5.86	0%	63.4°
2046-08-02 Thu	33	—	unknown	03:15–04:25 (good, 1.17 h)	72.6° 08:20	5.91	0%	78.0°
2046-08-03 Fri	35	—	unknown	03:10–04:30 (good, 1.33 h)	72.6° 08:20	5.97	3%	92.8°
2046-08-04 Sat	37	—	unknown	03:10–04:30 (good, 1.33 h)	72.6° 08:15	6.02	9%	107.7°
2046-08-05 Sun	39	—	unknown	03:05–04:30 (good, 1.42 h)	72.6° 08:10	6.08	17%	122.4°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-07-25&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.