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: 08-17 (100), 08-18 (100), 08-19 (100), 08-20 (100), 08-21 (100) — by astronomy; check the weather when the night is within four days.

2047-08-06astronomy score per night — click a bar for that night2047-09-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-08-06 Tue	38	—	unknown	00:15–04:35 (marginal, 4.33 h)	79.2° 05:55	6.12	99%	65.9°
2047-08-07 Wed	28	—	unknown	00:15–04:35 (marginal, 4.33 h)	79.2° 05:50	6.18	95%	53.6°
2047-08-08 Thu	23	—	unknown	00:15–04:35 (marginal, 4.33 h)	79.2° 05:45	6.24	90%	41.8°
2047-08-09 Fri	21	—	unknown	00:10–04:40 (marginal, 4.5 h)	79.2° 05:45	6.29	83%	30.6°
2047-08-10 Sat	27	—	unknown	23:55–04:40 (marginal, 4.75 h)	79.2° 05:40	6.35	75%	20.8°
2047-08-11 Sun	36	—	unknown	23:45–04:40 (marginal, 4.92 h)	79.2° 05:35	6.41	67%	14.8°
2047-08-12 Mon	49	—	unknown	02:10–03:45 (good, 1.58 h)	79.2° 05:30	6.47	57%	16.7°
2047-08-13 Tue	63	—	unknown	00:25–04:45 (good, 4.33 h)	79.2° 05:30	6.52	48%	24.8°
2047-08-14 Wed	80	—	unknown	23:55–04:45 (good, 4.83 h)	79.2° 05:25	6.58	39%	35.1°
2047-08-15 Thu	87	—	unknown	23:50–04:45 (good, 4.92 h)	79.2° 05:20	6.64	30%	46.3°
2047-08-16 Fri	94	—	unknown	23:50–04:50 (good, 5.0 h)	79.2° 05:15	6.7	21%	57.9°
2047-08-17 Sat	100	—	unknown	23:45–04:50 (good, 5.08 h)	79.2° 05:10	6.75	13%	70.1°
2047-08-18 Sun	100	—	unknown	23:40–04:50 (good, 5.17 h)	79.2° 05:10	6.81	7%	82.6°
2047-08-19 Mon	100	—	unknown	23:35–04:55 (good, 5.33 h)	79.2° 05:05	6.87	3%	95.5°
2047-08-20 Tue	100	—	unknown	23:35–04:55 (good, 5.33 h)	79.2° 05:00	6.93	0%	108.7°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-08-06&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.