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 North America Nebula: 08-11 (100), 08-12 (100), 08-13 (100), 08-14 (100), 08-15 (100) — by astronomy; check the weather when the night is within four days.

2029-08-11astronomy score per night — click a bar for that night2029-09-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-08-11 Sat	100	—	unknown	22:15–04:40 (good, 6.42 h)	87.2° 01:00	6.43	5%	127.2°
2029-08-12 Sun	100	—	unknown	22:15–04:45 (good, 6.5 h)	87.2° 00:55	6.49	11%	125.4°
2029-08-13 Mon	100	—	unknown	22:10–04:45 (good, 6.58 h)	87.2° 00:50	6.54	19%	121.2°
2029-08-14 Tue	100	—	unknown	22:10–04:45 (good, 6.58 h)	87.2° 00:45	6.6	29%	115.1°
2029-08-15 Wed	100	—	unknown	22:10–04:50 (good, 6.67 h)	87.2° 00:45	6.66	40%	107.8°
2029-08-16 Thu	100	—	unknown	22:05–04:50 (good, 6.75 h)	87.2° 00:40	6.72	52%	99.7°
2029-08-17 Fri	100	—	unknown	22:05–04:50 (good, 6.75 h)	87.2° 00:35	6.77	63%	91.3°
2029-08-18 Sat	100	—	unknown	22:05–04:50 (good, 6.75 h)	87.2° 00:30	6.83	73%	83.0°
2029-08-19 Sun	100	—	unknown	22:00–04:55 (good, 6.92 h)	87.2° 00:25	6.89	82%	75.1°
2029-08-20 Mon	97	—	unknown	22:00–04:55 (good, 6.92 h)	87.2° 00:25	6.95	90%	67.9°
2029-08-21 Tue	88	—	unknown	01:05–04:55 (good, 3.83 h)	87.2° 00:20	7.0	95%	61.7°
2029-08-22 Wed	57	—	unknown	21:55–05:00 (marginal, 7.08 h)	87.2° 00:15	7.06	98%	56.9°
2029-08-23 Thu	56	—	unknown	21:55–05:00 (marginal, 7.08 h)	87.2° 00:10	7.12	100%	53.9°
2029-08-24 Fri	56	—	unknown	21:50–05:00 (marginal, 7.17 h)	87.2° 00:05	7.17	99%	52.8°
2029-08-25 Sat	62	—	unknown	21:50–22:10 (good, 0.33 h)	87.2° 00:05	7.23	96%	53.8°
2029-08-26 Sun	67	—	unknown	21:45–23:10 (good, 1.42 h)	87.2° 00:00	7.29	92%	56.5°
2029-08-27 Mon	73	—	unknown	21:45–00:40 (good, 2.92 h)	87.2° 23:55	7.35	86%	60.8°
2029-08-28 Tue	78	—	unknown	21:45–02:55 (good, 5.17 h)	87.2° 23:50	7.4	79%	66.2°
2029-08-29 Wed	100	—	unknown	21:40–04:05 (good, 6.42 h)	87.2° 23:50	7.46	71%	72.3°
2029-08-30 Thu	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:45	7.51	62%	79.1°
2029-08-31 Fri	100	—	unknown	21:35–05:10 (good, 7.58 h)	87.2° 23:40	7.57	52%	86.2°
2029-09-01 Sat	100	—	unknown	21:35–05:10 (good, 7.58 h)	87.2° 23:35	7.63	43%	93.6°
2029-09-02 Sun	100	—	unknown	21:35–05:15 (good, 7.67 h)	87.2° 23:30	7.68	33%	101.0°
2029-09-03 Mon	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.2° 23:30	7.74	24%	108.2°
2029-09-04 Tue	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.2° 23:25	7.79	16%	115.0°
2029-09-05 Wed	100	—	unknown	21:25–05:20 (good, 7.92 h)	87.2° 23:20	7.85	8%	120.8°
2029-09-06 Thu	100	—	unknown	21:25–05:20 (good, 7.92 h)	87.2° 23:15	7.9	3%	125.1°
2029-09-07 Fri	100	—	unknown	21:25–05:20 (good, 7.92 h)	87.2° 23:10	7.96	0%	127.1°
2029-09-08 Sat	100	—	unknown	21:20–05:20 (good, 8.0 h)	87.2° 23:10	8.01	0%	126.4°
2029-09-09 Sun	100	—	unknown	21:20–05:25 (good, 8.08 h)	87.2° 23:05	8.07	3%	122.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-08-11&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.