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: 09-24 (100), 09-25 (100), 09-26 (100), 09-27 (100), 09-28 (100) — by astronomy; check the weather when the night is within four days.

2046-09-16astronomy score per night — click a bar for that night2046-10-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-09-16 Sun	25	—	unknown	21:55–01:00 (marginal, 3.08 h)	79.2° 03:15	8.43	97%	25.2°
2046-09-17 Mon	27	—	unknown	21:40–02:15 (marginal, 4.58 h)	79.2° 03:10	8.49	94%	16.9°
2046-09-18 Tue	35	—	unknown	21:25–05:35 (marginal, 8.17 h)	79.2° 03:05	8.54	88%	14.5°
2046-09-19 Wed	46	—	unknown	21:15–05:35 (marginal, 8.33 h)	79.2° 03:00	8.59	82%	20.4°
2046-09-20 Thu	62	—	unknown	21:30–21:35 (good, 0.08 h)	79.2° 02:55	8.64	73%	30.2°
2046-09-21 Fri	83	—	unknown	21:25–02:50 (good, 5.42 h)	79.2° 02:55	8.69	64%	41.3°
2046-09-22 Sat	89	—	unknown	21:20–05:40 (good, 8.33 h)	79.2° 02:50	8.74	54%	53.2°
2046-09-23 Sun	97	—	unknown	21:20–05:40 (good, 8.33 h)	79.2° 02:45	8.79	44%	65.6°
2046-09-24 Mon	100	—	unknown	21:15–05:40 (good, 8.42 h)	79.2° 02:40	8.84	33%	78.5°
2046-09-25 Tue	100	—	unknown	21:10–05:40 (good, 8.5 h)	79.2° 02:40	8.89	23%	91.9°
2046-09-26 Wed	100	—	unknown	21:05–05:45 (good, 8.67 h)	79.2° 02:35	8.94	14%	105.7°
2046-09-27 Thu	100	—	unknown	21:00–05:45 (good, 8.75 h)	79.2° 02:30	8.99	7%	119.9°
2046-09-28 Fri	100	—	unknown	21:00–05:45 (good, 8.75 h)	79.2° 02:25	9.04	2%	134.2°
2046-09-29 Sat	100	—	unknown	20:55–05:45 (good, 8.83 h)	79.2° 02:20	9.09	0%	148.2°
2046-09-30 Sun	100	—	unknown	20:50–05:50 (good, 9.0 h)	79.2° 02:20	9.14	1%	160.4°
2046-10-01 Mon	100	—	unknown	20:45–05:50 (good, 9.08 h)	79.2° 02:15	9.19	5%	165.6°
2046-10-02 Tue	100	—	unknown	20:45–05:50 (good, 9.08 h)	79.2° 02:10	9.24	12%	158.3°
2046-10-03 Wed	100	—	unknown	20:40–05:50 (good, 9.17 h)	79.2° 02:05	9.28	20%	146.3°
2046-10-04 Thu	100	—	unknown	20:35–05:50 (good, 9.25 h)	79.2° 02:00	9.33	30%	133.4°
2046-10-05 Fri	100	—	unknown	20:35–05:55 (good, 9.33 h)	79.2° 02:00	9.38	40%	120.6°
2046-10-06 Sat	100	—	unknown	20:35–05:55 (good, 9.33 h)	79.2° 01:55	9.42	51%	108.1°
2046-10-07 Sun	100	—	unknown	20:35–05:55 (good, 9.33 h)	79.2° 01:50	9.47	61%	95.9°
2046-10-08 Mon	100	—	unknown	20:45–05:55 (good, 9.17 h)	79.2° 01:45	9.52	70%	83.9°
2046-10-09 Tue	100	—	unknown	21:35–06:00 (good, 8.42 h)	79.2° 01:45	9.56	78%	72.1°
2046-10-10 Wed	100	—	unknown	23:30–06:00 (good, 6.5 h)	79.2° 01:40	9.61	86%	60.6°
2046-10-11 Thu	93	—	unknown	03:10–06:00 (good, 2.83 h)	79.2° 01:35	9.65	92%	49.3°
2046-10-12 Fri	85	—	unknown	05:55–06:00 (good, 0.08 h)	79.2° 01:30	9.7	96%	38.2°
2046-10-13 Sat	39	—	unknown	01:50–06:00 (marginal, 4.17 h)	79.2° 01:25	9.74	99%	27.8°
2046-10-14 Sun	31	—	unknown	03:15–06:05 (marginal, 2.83 h)	79.2° 01:25	9.78	100%	18.7°
2046-10-15 Mon	30	—	unknown	20:15–23:15 (marginal, 3.0 h)	79.2° 01:20	9.83	99%	14.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-09-16&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.