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: 09-05 (100), 09-04 (94), 09-03 (87), 08-20 (73), 08-19 (72) — by astronomy; check the weather when the night is within four days.

2029-08-07astronomy score per night — click a bar for that night2029-09-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-08-07 Tue	43	—	unknown	02:55–04:35 (good, 1.67 h)	72.5° 08:00	6.2	6%	48.9°
2029-08-08 Wed	46	—	unknown	02:50–04:35 (good, 1.75 h)	72.5° 07:55	6.26	2%	62.4°
2029-08-09 Thu	49	—	unknown	02:50–04:40 (good, 1.83 h)	72.5° 07:55	6.31	0%	76.3°
2029-08-10 Fri	51	—	unknown	02:45–04:40 (good, 1.92 h)	72.5° 07:50	6.37	1%	90.4°
2029-08-11 Sat	53	—	unknown	02:40–04:40 (good, 2.0 h)	72.5° 07:45	6.43	5%	104.7°
2029-08-12 Sun	56	—	unknown	02:35–04:45 (good, 2.17 h)	72.5° 07:40	6.49	11%	119.2°
2029-08-13 Mon	58	—	unknown	02:30–04:45 (good, 2.25 h)	72.5° 07:40	6.54	19%	133.7°
2029-08-14 Tue	59	—	unknown	02:30–04:45 (good, 2.25 h)	72.5° 07:35	6.6	29%	148.1°
2029-08-15 Wed	63	—	unknown	02:25–04:50 (good, 2.42 h)	72.5° 07:30	6.66	40%	162.4°
2029-08-16 Thu	65	—	unknown	02:20–04:50 (good, 2.5 h)	72.5° 07:25	6.72	52%	176.4°
2029-08-17 Fri	67	—	unknown	02:15–04:50 (good, 2.58 h)	72.5° 07:20	6.77	63%	169.4°
2029-08-18 Sat	69	—	unknown	02:10–04:50 (good, 2.67 h)	72.5° 07:20	6.83	73%	155.7°
2029-08-19 Sun	72	—	unknown	02:15–04:55 (good, 2.67 h)	72.5° 07:15	6.89	82%	142.2°
2029-08-20 Mon	73	—	unknown	02:10–04:55 (good, 2.75 h)	72.5° 07:10	6.95	90%	128.8°
2029-08-21 Tue	70	—	unknown	02:10–04:55 (good, 2.75 h)	72.5° 07:05	7.0	95%	115.7°
2029-08-22 Wed	55	—	unknown	02:20–05:00 (good, 2.67 h)	72.5° 07:00	7.06	98%	102.8°
2029-08-23 Thu	45	—	unknown	03:00–05:00 (good, 2.0 h)	72.5° 07:00	7.12	100%	90.1°
2029-08-24 Fri	36	—	unknown	04:10–05:00 (good, 0.83 h)	72.5° 06:55	7.17	99%	77.6°
2029-08-25 Sat	28	—	unknown	01:40–05:05 (marginal, 3.42 h)	72.5° 06:50	7.23	96%	65.3°
2029-08-26 Sun	21	—	unknown	01:45–05:05 (marginal, 3.33 h)	72.5° 06:45	7.29	92%	53.2°
2029-08-27 Mon	17	—	unknown	01:45–05:05 (marginal, 3.33 h)	72.5° 06:45	7.35	86%	41.2°
2029-08-28 Tue	16	—	unknown	01:40–05:05 (marginal, 3.42 h)	72.5° 06:40	7.4	79%	29.4°
2029-08-29 Wed	22	—	unknown	01:20–05:10 (marginal, 3.83 h)	72.5° 06:35	7.46	71%	17.6°
2029-08-30 Thu	30	—	unknown	01:05–05:10 (marginal, 4.08 h)	72.5° 06:30	7.51	62%	5.8°
2029-08-31 Fri	41	—	unknown	03:25–05:10 (good, 1.75 h)	72.5° 06:25	7.57	52%	6.4°
2029-09-01 Sat	54	—	unknown	01:40–05:10 (good, 3.5 h)	72.5° 06:25	7.63	43%	18.5°
2029-09-02 Sun	70	—	unknown	01:25–05:15 (good, 3.83 h)	72.5° 06:20	7.68	33%	30.9°
2029-09-03 Mon	87	—	unknown	01:10–05:15 (good, 4.08 h)	72.5° 06:15	7.74	24%	43.7°
2029-09-04 Tue	94	—	unknown	01:05–05:15 (good, 4.17 h)	72.5° 06:10	7.79	16%	56.9°
2029-09-05 Wed	100	—	unknown	01:00–05:20 (good, 4.33 h)	72.5° 06:05	7.85	8%	70.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-08-07&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.