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: 10-21 (100), 10-22 (100), 10-23 (100), 10-24 (100), 10-25 (100) — by astronomy; check the weather when the night is within four days.

2046-10-17astronomy score per night — click a bar for that night2046-11-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-10-17 Wed	44	—	unknown	20:10–01:45 (marginal, 5.58 h)	79.2° 01:10	9.91	92%	27.7°
2046-10-18 Thu	81	—	unknown	20:10–20:20 (good, 0.17 h)	79.2° 01:05	9.96	86%	38.6°
2046-10-19 Fri	87	—	unknown	20:10–00:25 (good, 4.25 h)	79.2° 01:05	10.0	78%	50.2°
2046-10-20 Sat	95	—	unknown	20:05–04:00 (good, 7.92 h)	79.2° 01:00	10.04	70%	62.3°
2046-10-21 Sun	100	—	unknown	20:05–05:35 (good, 9.5 h)	79.2° 00:55	10.08	60%	74.8°
2046-10-22 Mon	100	—	unknown	20:05–06:05 (good, 10.0 h)	79.2° 00:50	10.12	49%	87.6°
2046-10-23 Tue	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.2° 00:50	10.16	38%	100.8°
2046-10-24 Wed	100	—	unknown	20:00–06:10 (good, 10.17 h)	79.2° 00:45	10.2	28%	114.4°
2046-10-25 Thu	100	—	unknown	20:00–06:10 (good, 10.17 h)	79.2° 00:40	10.24	18%	128.3°
2046-10-26 Fri	100	—	unknown	20:00–06:10 (good, 10.17 h)	79.2° 00:35	10.28	10%	142.1°
2046-10-27 Sat	100	—	unknown	20:00–05:05 (good, 10.08 h)	79.2° 00:30	10.32	4%	155.2°
2046-10-28 Sun	100	—	unknown	18:55–05:00 (good, 10.08 h)	79.2° 23:30	10.36	1%	164.7°
2046-10-29 Mon	100	—	unknown	18:55–04:55 (good, 10.0 h)	79.2° 23:25	10.4	0%	162.7°
2046-10-30 Tue	100	—	unknown	18:55–04:55 (good, 10.0 h)	79.2° 23:20	10.43	3%	151.7°
2046-10-31 Wed	100	—	unknown	18:55–04:50 (good, 9.92 h)	79.2° 23:15	10.47	8%	138.7°
2046-11-01 Thu	100	—	unknown	18:50–04:45 (good, 9.92 h)	79.2° 23:10	10.51	16%	125.4°
2046-11-02 Fri	100	—	unknown	18:50–04:40 (good, 9.83 h)	79.2° 23:10	10.54	25%	112.4°
2046-11-03 Sat	100	—	unknown	18:50–04:35 (good, 9.75 h)	79.2° 23:05	10.58	34%	99.7°
2046-11-04 Sun	100	—	unknown	18:50–04:35 (good, 9.75 h)	79.2° 23:00	10.61	44%	87.4°
2046-11-05 Mon	100	—	unknown	18:50–04:30 (good, 9.67 h)	79.2° 22:55	10.65	54%	75.4°
2046-11-06 Tue	100	—	unknown	18:45–04:25 (good, 9.67 h)	79.2° 22:55	10.68	63%	63.7°
2046-11-07 Wed	95	—	unknown	20:15–04:20 (good, 8.08 h)	79.2° 22:50	10.72	72%	52.3°
2046-11-08 Thu	87	—	unknown	00:40–04:15 (good, 3.58 h)	79.2° 22:45	10.75	80%	41.1°
2046-11-09 Fri	75	—	unknown	03:50–04:15 (good, 0.42 h)	79.2° 22:40	10.78	87%	30.5°
2046-11-10 Sat	41	—	unknown	18:45–04:25 (marginal, 9.67 h)	79.2° 22:35	10.81	93%	20.9°
2046-11-11 Sun	29	—	unknown	00:40–04:05 (marginal, 3.42 h)	79.2° 22:35	10.84	97%	14.7°
2046-11-12 Mon	26	—	unknown	18:40–20:45 (marginal, 2.08 h)	79.2° 22:30	10.87	99%	16.7°
2046-11-13 Tue	28	—	unknown	18:40–21:15 (marginal, 2.58 h)	79.2° 22:25	10.91	100%	25.1°
2046-11-14 Wed	40	—	unknown	18:40–23:05 (marginal, 4.42 h)	79.2° 22:20	10.93	98%	35.9°
2046-11-15 Thu	58	—	unknown	18:40–03:25 (marginal, 8.75 h)	79.2° 22:15	10.96	95%	47.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-10-17&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.