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: 09-20 (100), 09-21 (100), 09-22 (100), 09-23 (100), 09-24 (100) — by astronomy; check the weather when the night is within four days.

2030-09-18astronomy score per night — click a bar for that night2030-10-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-09-18 Wed	88	—	unknown	21:40–05:35 (good, 7.92 h)	79.1° 03:05	8.53	58%	46.6°
2030-09-19 Thu	94	—	unknown	21:35–05:35 (good, 8.0 h)	79.1° 03:00	8.58	49%	57.7°
2030-09-20 Fri	100	—	unknown	21:30–05:35 (good, 8.08 h)	79.1° 02:55	8.63	40%	69.0°
2030-09-21 Sat	100	—	unknown	21:25–05:35 (good, 8.17 h)	79.1° 02:55	8.69	30%	80.6°
2030-09-22 Sun	100	—	unknown	21:20–05:40 (good, 8.33 h)	79.1° 02:50	8.74	22%	92.5°
2030-09-23 Mon	100	—	unknown	21:20–05:40 (good, 8.33 h)	79.1° 02:45	8.79	14%	104.7°
2030-09-24 Tue	100	—	unknown	21:15–05:40 (good, 8.42 h)	79.1° 02:40	8.84	8%	117.1°
2030-09-25 Wed	100	—	unknown	21:10–05:40 (good, 8.5 h)	79.1° 02:35	8.89	3%	129.7°
2030-09-26 Thu	100	—	unknown	21:05–05:45 (good, 8.67 h)	79.1° 02:35	8.94	0%	142.3°
2030-09-27 Fri	100	—	unknown	21:00–05:45 (good, 8.75 h)	79.1° 02:30	8.99	0%	154.1°
2030-09-28 Sat	100	—	unknown	21:00–05:45 (good, 8.75 h)	79.1° 02:25	9.04	3%	162.6°
2030-09-29 Sun	100	—	unknown	20:55–05:45 (good, 8.83 h)	79.1° 02:20	9.08	8%	161.7°
2030-09-30 Mon	100	—	unknown	20:50–05:50 (good, 9.0 h)	79.1° 02:20	9.13	16%	152.2°
2030-10-01 Tue	100	—	unknown	20:50–05:50 (good, 9.0 h)	79.1° 02:15	9.18	25%	139.8°
2030-10-02 Wed	100	—	unknown	20:45–05:50 (good, 9.08 h)	79.1° 02:10	9.23	36%	126.6°
2030-10-03 Thu	100	—	unknown	20:45–05:50 (good, 9.08 h)	79.1° 02:05	9.28	47%	113.2°
2030-10-04 Fri	100	—	unknown	20:45–05:50 (good, 9.08 h)	79.1° 02:00	9.32	58%	99.8°
2030-10-05 Sat	100	—	unknown	20:55–05:55 (good, 9.0 h)	79.1° 02:00	9.37	69%	86.6°
2030-10-06 Sun	100	—	unknown	21:50–05:55 (good, 8.08 h)	79.1° 01:55	9.42	79%	73.6°
2030-10-07 Mon	100	—	unknown	00:10–05:55 (good, 5.75 h)	79.1° 01:50	9.46	87%	60.8°
2030-10-08 Tue	91	—	unknown	03:40–05:55 (good, 2.25 h)	79.1° 01:45	9.51	93%	48.5°
2030-10-09 Wed	52	—	unknown	20:25–06:00 (marginal, 9.58 h)	79.1° 01:40	9.56	97%	36.7°
2030-10-10 Thu	35	—	unknown	02:25–06:00 (marginal, 3.58 h)	79.1° 01:40	9.6	100%	26.0°
2030-10-11 Fri	28	—	unknown	20:20–23:10 (marginal, 2.83 h)	79.1° 01:35	9.65	100%	18.1°
2030-10-12 Sat	33	—	unknown	20:20–00:00 (marginal, 3.67 h)	79.1° 01:30	9.69	98%	16.9°
2030-10-13 Sun	40	—	unknown	20:20–01:20 (marginal, 5.0 h)	79.1° 01:25	9.74	94%	23.2°
2030-10-14 Mon	76	—	unknown	20:15–20:20 (good, 0.08 h)	79.1° 01:25	9.78	89%	32.6°
2030-10-15 Tue	85	—	unknown	20:15–23:15 (good, 3.0 h)	79.1° 01:20	9.82	82%	43.2°
2030-10-16 Wed	91	—	unknown	20:15–02:10 (good, 5.92 h)	79.1° 01:15	9.87	75%	54.1°
2030-10-17 Thu	99	—	unknown	20:10–04:45 (good, 8.58 h)	79.1° 01:10	9.91	66%	65.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-09-18&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.