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 Triangulum Pinwheel: 08-24 (100), 08-25 (100), 08-26 (100), 08-27 (100), 08-28 (100) — by astronomy; check the weather when the night is within four days.

2030-08-15astronomy score per night — click a bar for that night2030-09-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-08-15 Thu	24	—	unknown	23:50–04:50 (marginal, 5.0 h)	79.1° 05:20	6.64	92%	40.2°
2030-08-16 Fri	21	—	unknown	23:45–04:50 (marginal, 5.08 h)	79.1° 05:15	6.7	86%	29.0°
2030-08-17 Sat	29	—	unknown	23:30–04:50 (marginal, 5.33 h)	79.1° 05:10	6.76	78%	19.8°
2030-08-18 Sun	39	—	unknown	23:15–04:50 (marginal, 5.58 h)	79.1° 05:05	6.82	70%	16.1°
2030-08-19 Mon	53	—	unknown	02:05–02:55 (good, 0.83 h)	79.1° 05:05	6.87	61%	20.3°
2030-08-20 Tue	69	—	unknown	23:55–04:55 (good, 5.0 h)	79.1° 05:00	6.93	51%	29.1°
2030-08-21 Wed	84	—	unknown	23:30–04:55 (good, 5.42 h)	79.1° 04:55	6.99	42%	39.4°
2030-08-22 Thu	90	—	unknown	23:25–05:00 (good, 5.58 h)	79.1° 04:50	7.05	33%	50.3°
2030-08-23 Fri	97	—	unknown	23:20–05:00 (good, 5.67 h)	79.1° 04:45	7.1	24%	61.5°
2030-08-24 Sat	100	—	unknown	23:15–05:00 (good, 5.75 h)	79.1° 04:45	7.16	16%	73.1°
2030-08-25 Sun	100	—	unknown	23:10–05:00 (good, 5.83 h)	79.1° 04:40	7.22	10%	84.9°
2030-08-26 Mon	100	—	unknown	23:10–05:05 (good, 5.92 h)	79.1° 04:35	7.27	5%	97.0°
2030-08-27 Tue	100	—	unknown	23:05–05:05 (good, 6.0 h)	79.1° 04:30	7.33	1%	109.3°
2030-08-28 Wed	100	—	unknown	23:00–05:05 (good, 6.08 h)	79.1° 04:25	7.39	0%	121.8°
2030-08-29 Thu	100	—	unknown	22:55–05:10 (good, 6.25 h)	79.1° 04:25	7.44	1%	134.4°
2030-08-30 Fri	100	—	unknown	22:50–05:10 (good, 6.33 h)	79.1° 04:20	7.5	5%	146.6°
2030-08-31 Sat	100	—	unknown	22:50–05:10 (good, 6.33 h)	79.1° 04:15	7.56	11%	157.6°
2030-09-01 Sun	100	—	unknown	22:45–05:10 (good, 6.42 h)	79.1° 04:10	7.61	18%	163.7°
2030-09-02 Mon	100	—	unknown	22:40–05:15 (good, 6.58 h)	79.1° 04:10	7.67	28%	159.7°
2030-09-03 Tue	100	—	unknown	22:40–05:15 (good, 6.58 h)	79.1° 04:05	7.72	39%	149.2°
2030-09-04 Wed	100	—	unknown	22:35–05:15 (good, 6.67 h)	79.1° 04:00	7.78	50%	136.7°
2030-09-05 Thu	100	—	unknown	22:35–05:15 (good, 6.67 h)	79.1° 03:55	7.83	62%	123.6°
2030-09-06 Fri	100	—	unknown	22:35–05:20 (good, 6.75 h)	79.1° 03:50	7.89	72%	110.2°
2030-09-07 Sat	100	—	unknown	22:40–05:20 (good, 6.67 h)	79.1° 03:50	7.94	82%	96.7°
2030-09-08 Sun	100	—	unknown	23:20–05:20 (good, 6.0 h)	79.1° 03:45	8.0	90%	83.3°
2030-09-09 Mon	100	—	unknown	01:05–05:25 (good, 4.33 h)	79.1° 03:40	8.05	95%	70.1°
2030-09-10 Tue	65	—	unknown	04:25–05:25 (good, 1.0 h)	79.1° 03:35	8.11	99%	57.2°
2030-09-11 Wed	43	—	unknown	22:10–05:25 (marginal, 7.25 h)	79.1° 03:30	8.16	100%	44.7°
2030-09-12 Thu	28	—	unknown	22:15–05:25 (marginal, 7.17 h)	79.1° 03:30	8.21	99%	33.1°
2030-09-13 Fri	24	—	unknown	22:00–02:00 (marginal, 4.0 h)	79.1° 03:25	8.27	95%	22.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-08-15&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.