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: 09-08 (100), 09-09 (100), 09-10 (100), 09-11 (100), 09-12 (100) — by astronomy; check the weather when the night is within four days.

2042-08-29astronomy score per night — click a bar for that night2042-09-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-08-29 Fri	75	—	unknown	01:00–05:10 (good, 4.17 h)	79.2° 04:25	7.45	98%	74.9°
2042-08-30 Sat	59	—	unknown	04:20–05:10 (good, 0.83 h)	79.2° 04:20	7.51	100%	61.1°
2042-08-31 Sun	39	—	unknown	22:40–05:10 (marginal, 6.5 h)	79.2° 04:15	7.56	99%	47.4°
2042-09-01 Mon	26	—	unknown	22:40–05:10 (marginal, 6.5 h)	79.2° 04:10	7.62	95%	34.3°
2042-09-02 Tue	29	—	unknown	22:30–05:15 (marginal, 6.75 h)	79.2° 04:10	7.67	88%	23.1°
2042-09-03 Wed	39	—	unknown	22:15–05:15 (marginal, 7.0 h)	79.2° 04:05	7.73	80%	18.0°
2042-09-04 Thu	53	—	unknown	22:05–05:15 (marginal, 7.17 h)	79.2° 04:00	7.78	70%	22.9°
2042-09-05 Fri	73	—	unknown	22:55–03:30 (good, 4.58 h)	79.2° 03:55	7.84	59%	33.3°
2042-09-06 Sat	85	—	unknown	22:25–05:20 (good, 6.92 h)	79.2° 03:50	7.89	48%	45.3°
2042-09-07 Sun	91	—	unknown	22:20–05:20 (good, 7.0 h)	79.2° 03:50	7.95	37%	57.7°
2042-09-08 Mon	100	—	unknown	22:15–05:20 (good, 7.08 h)	79.2° 03:45	8.0	27%	70.0°
2042-09-09 Tue	100	—	unknown	22:15–05:25 (good, 7.17 h)	79.2° 03:40	8.06	18%	82.2°
2042-09-10 Wed	100	—	unknown	22:10–05:25 (good, 7.25 h)	79.2° 03:35	8.11	11%	94.3°
2042-09-11 Thu	100	—	unknown	22:05–05:25 (good, 7.33 h)	79.2° 03:35	8.17	6%	106.1°
2042-09-12 Fri	100	—	unknown	22:00–05:25 (good, 7.42 h)	79.2° 03:30	8.22	2%	117.7°
2042-09-13 Sat	100	—	unknown	21:55–05:30 (good, 7.58 h)	79.2° 03:25	8.27	0%	129.0°
2042-09-14 Sun	100	—	unknown	21:55–05:30 (good, 7.58 h)	79.2° 03:20	8.33	0%	139.8°
2042-09-15 Mon	100	—	unknown	21:50–05:30 (good, 7.67 h)	79.2° 03:15	8.38	2%	149.8°
2042-09-16 Tue	100	—	unknown	21:45–05:30 (good, 7.75 h)	79.2° 03:15	8.43	6%	158.1°
2042-09-17 Wed	100	—	unknown	21:40–05:35 (good, 7.92 h)	79.2° 03:10	8.48	11%	162.1°
2042-09-18 Thu	100	—	unknown	21:40–05:35 (good, 7.92 h)	79.2° 03:05	8.54	18%	159.2°
2042-09-19 Fri	100	—	unknown	21:35–05:35 (good, 8.0 h)	79.2° 03:00	8.59	25%	151.4°
2042-09-20 Sat	100	—	unknown	21:30–05:35 (good, 8.08 h)	79.2° 02:55	8.64	34%	141.5°
2042-09-21 Sun	100	—	unknown	21:30–05:35 (good, 8.08 h)	79.2° 02:55	8.69	44%	130.5°
2042-09-22 Mon	100	—	unknown	21:25–05:40 (good, 8.25 h)	79.2° 02:50	8.74	54%	118.9°
2042-09-23 Tue	100	—	unknown	21:30–05:40 (good, 8.17 h)	79.2° 02:45	8.79	64%	106.7°
2042-09-24 Wed	100	—	unknown	21:30–05:40 (good, 8.17 h)	79.2° 02:40	8.84	74%	94.1°
2042-09-25 Thu	100	—	unknown	21:50–05:40 (good, 7.83 h)	79.2° 02:40	8.89	83%	80.9°
2042-09-26 Fri	100	—	unknown	23:35–05:45 (good, 6.17 h)	79.2° 02:35	8.94	91%	67.4°
2042-09-27 Sat	94	—	unknown	03:45–05:45 (good, 2.0 h)	79.2° 02:30	8.99	96%	53.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-08-29&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.