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: 09-19 (100), 09-20 (100), 09-21 (100), 09-22 (100), 10-03 (100) — by astronomy; check the weather when the night is within four days.

2045-09-19astronomy score per night — click a bar for that night2045-10-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-09-19 Tue	100	—	unknown	21:45–05:35 (good, 7.83 h)	79.2° 03:00	8.6	68%	105.1°
2045-09-20 Wed	100	—	unknown	21:50–05:35 (good, 7.75 h)	79.2° 02:55	8.65	76%	93.6°
2045-09-21 Thu	100	—	unknown	22:10–05:40 (good, 7.5 h)	79.2° 02:50	8.7	84%	82.1°
2045-09-22 Fri	100	—	unknown	23:35–05:40 (good, 6.08 h)	79.2° 02:50	8.75	90%	70.7°
2045-09-23 Sat	99	—	unknown	02:35–05:40 (good, 3.08 h)	79.2° 02:45	8.81	95%	59.3°
2045-09-24 Sun	60	—	unknown	05:15–05:40 (good, 0.42 h)	79.2° 02:40	8.86	98%	47.9°
2045-09-25 Mon	42	—	unknown	21:20–05:40 (marginal, 8.33 h)	79.2° 02:35	8.91	100%	36.7°
2045-09-26 Tue	29	—	unknown	03:25–05:45 (marginal, 2.33 h)	79.2° 02:35	8.96	100%	26.1°
2045-09-27 Wed	27	—	unknown	21:00–00:35 (marginal, 3.58 h)	79.2° 02:30	9.0	97%	17.3°
2045-09-28 Thu	33	—	unknown	20:45–01:55 (marginal, 5.17 h)	79.2° 02:25	9.05	93%	14.8°
2045-09-29 Fri	43	—	unknown	20:40–05:45 (marginal, 9.08 h)	79.2° 02:20	9.1	87%	21.4°
2045-09-30 Sat	66	—	unknown	20:50–21:00 (good, 0.17 h)	79.2° 02:15	9.15	79%	32.0°
2045-10-01 Sun	83	—	unknown	20:45–01:40 (good, 4.92 h)	79.2° 02:15	9.2	70%	44.0°
2045-10-02 Mon	91	—	unknown	20:40–05:30 (good, 8.83 h)	79.2° 02:10	9.25	59%	56.7°
2045-10-03 Tue	100	—	unknown	20:40–05:50 (good, 9.17 h)	79.2° 02:05	9.29	48%	69.9°
2045-10-04 Wed	100	—	unknown	20:35–05:55 (good, 9.33 h)	79.2° 02:00	9.34	37%	83.4°
2045-10-05 Thu	100	—	unknown	20:30–05:55 (good, 9.42 h)	79.2° 01:55	9.39	26%	97.3°
2045-10-06 Fri	100	—	unknown	20:30–05:55 (good, 9.42 h)	79.2° 01:55	9.43	17%	111.3°
2045-10-07 Sat	100	—	unknown	20:25–05:55 (good, 9.5 h)	79.2° 01:50	9.48	9%	125.4°
2045-10-08 Sun	100	—	unknown	20:25–05:55 (good, 9.5 h)	79.2° 01:45	9.53	3%	139.3°
2045-10-09 Mon	100	—	unknown	20:25–06:00 (good, 9.58 h)	79.2° 01:40	9.57	0%	152.4°
2045-10-10 Tue	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.2° 01:40	9.62	0%	162.9°
2045-10-11 Wed	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.2° 01:35	9.66	3%	164.6°
2045-10-12 Thu	100	—	unknown	20:20–06:00 (good, 9.67 h)	79.2° 01:30	9.71	8%	156.2°
2045-10-13 Fri	100	—	unknown	20:15–06:00 (good, 9.75 h)	79.2° 01:25	9.75	15%	144.7°
2045-10-14 Sat	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.2° 01:20	9.79	23%	132.7°
2045-10-15 Sun	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.2° 01:20	9.84	32%	120.7°
2045-10-16 Mon	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.2° 01:15	9.88	42%	108.8°
2045-10-17 Tue	100	—	unknown	20:10–06:05 (good, 9.92 h)	79.2° 01:10	9.92	51%	97.2°
2045-10-18 Wed	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.2° 01:05	9.97	61%	85.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-09-19&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.