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: 08-21 (100), 08-22 (100), 08-23 (100), 08-24 (100), 08-25 (100) — by astronomy; check the weather when the night is within four days.

2047-08-21astronomy score per night — click a bar for that night2047-09-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-08-21 Wed	100	—	unknown	23:30–04:55 (good, 5.42 h)	79.2° 04:55	6.98	0%	122.1°
2047-08-22 Thu	100	—	unknown	23:25–05:00 (good, 5.58 h)	79.2° 04:50	7.04	3%	135.6°
2047-08-23 Fri	100	—	unknown	23:20–05:00 (good, 5.67 h)	79.2° 04:50	7.1	9%	148.6°
2047-08-24 Sat	100	—	unknown	23:15–05:00 (good, 5.75 h)	79.2° 04:45	7.15	16%	160.2°
2047-08-25 Sun	100	—	unknown	23:15–05:00 (good, 5.75 h)	79.2° 04:40	7.21	26%	165.5°
2047-08-26 Mon	100	—	unknown	23:10–05:05 (good, 5.92 h)	79.2° 04:35	7.27	36%	159.2°
2047-08-27 Tue	100	—	unknown	23:10–05:05 (good, 5.92 h)	79.2° 04:35	7.33	48%	147.6°
2047-08-28 Wed	100	—	unknown	23:05–05:05 (good, 6.0 h)	79.2° 04:30	7.38	59%	134.8°
2047-08-29 Thu	100	—	unknown	23:05–05:10 (good, 6.08 h)	79.2° 04:25	7.44	70%	121.6°
2047-08-30 Fri	100	—	unknown	23:05–05:10 (good, 6.08 h)	79.2° 04:20	7.49	80%	108.5°
2047-08-31 Sat	100	—	unknown	23:10–05:10 (good, 6.0 h)	79.2° 04:15	7.55	88%	95.5°
2047-09-01 Sun	100	—	unknown	00:05–05:10 (good, 5.08 h)	79.2° 04:15	7.61	94%	82.6°
2047-09-02 Mon	73	—	unknown	01:40–05:15 (good, 3.58 h)	79.2° 04:10	7.66	98%	70.0°
2047-09-03 Tue	56	—	unknown	04:55–05:15 (good, 0.33 h)	79.2° 04:05	7.72	100%	57.7°
2047-09-04 Wed	38	—	unknown	22:35–05:15 (marginal, 6.67 h)	79.2° 04:00	7.77	100%	45.7°
2047-09-05 Thu	25	—	unknown	22:40–05:15 (marginal, 6.58 h)	79.2° 03:55	7.83	97%	34.3°
2047-09-06 Fri	23	—	unknown	22:30–05:20 (marginal, 6.83 h)	79.2° 03:55	7.88	93%	23.9°
2047-09-07 Sat	29	—	unknown	22:15–05:20 (marginal, 7.08 h)	79.2° 03:50	7.94	88%	16.2°
2047-09-08 Sun	38	—	unknown	22:00–05:20 (marginal, 7.33 h)	79.2° 03:45	7.99	81%	15.3°
2047-09-09 Mon	51	—	unknown	21:45–05:20 (marginal, 7.58 h)	79.2° 03:40	8.05	73%	22.0°
2047-09-10 Tue	69	—	unknown	23:10–01:50 (good, 2.67 h)	79.2° 03:40	8.1	64%	31.7°
2047-09-11 Wed	84	—	unknown	22:05–05:25 (good, 7.33 h)	79.2° 03:35	8.16	55%	42.5°
2047-09-12 Thu	91	—	unknown	22:00–05:25 (good, 7.42 h)	79.2° 03:30	8.21	46%	53.8°
2047-09-13 Fri	98	—	unknown	22:00–05:30 (good, 7.5 h)	79.2° 03:25	8.26	36%	65.5°
2047-09-14 Sat	100	—	unknown	21:55–05:30 (good, 7.58 h)	79.2° 03:20	8.32	27%	77.7°
2047-09-15 Sun	100	—	unknown	21:50–05:30 (good, 7.67 h)	79.2° 03:20	8.37	18%	90.3°
2047-09-16 Mon	100	—	unknown	21:45–05:30 (good, 7.75 h)	79.2° 03:15	8.42	10%	103.2°
2047-09-17 Tue	100	—	unknown	21:45–05:30 (good, 7.75 h)	79.2° 03:10	8.47	5%	116.6°
2047-09-18 Wed	100	—	unknown	21:40–05:35 (good, 7.92 h)	79.2° 03:05	8.52	1%	130.2°
2047-09-19 Thu	100	—	unknown	21:35–05:35 (good, 8.0 h)	79.2° 03:00	8.58	0%	143.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-08-21&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.