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: 10-19 (100), 10-20 (100), 10-21 (100), 10-22 (100), 10-23 (100) — by astronomy; check the weather when the night is within four days.

2031-10-19astronomy score per night — click a bar for that night2031-11-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-10-19 Sun	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.1° 01:05	9.98	15%	136.6°
2031-10-20 Mon	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.1° 01:00	10.02	24%	123.7°
2031-10-21 Tue	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.1° 00:55	10.07	34%	110.4°
2031-10-22 Wed	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.1° 00:50	10.11	46%	97.0°
2031-10-23 Thu	100	—	unknown	20:05–06:15 (good, 10.17 h)	79.1° 00:50	10.15	57%	83.6°
2031-10-24 Fri	100	—	unknown	20:15–06:15 (good, 10.0 h)	79.1° 00:45	10.19	68%	70.2°
2031-10-25 Sat	98	—	unknown	22:15–05:15 (good, 8.0 h)	79.1° 00:40	10.23	78%	57.0°
2031-10-26 Sun	89	—	unknown	01:40–05:10 (good, 3.5 h)	79.1° 23:35	10.27	87%	44.2°
2031-10-27 Mon	79	—	unknown	04:35–05:05 (good, 0.5 h)	79.1° 23:35	10.31	93%	32.2°
2031-10-28 Tue	38	—	unknown	00:25–05:10 (marginal, 4.75 h)	79.1° 23:30	10.34	98%	22.3°
2031-10-29 Wed	30	—	unknown	18:55–21:30 (marginal, 2.58 h)	79.1° 23:25	10.38	100%	17.9°
2031-10-30 Thu	33	—	unknown	18:55–22:05 (marginal, 3.17 h)	79.1° 23:20	10.42	100%	22.0°
2031-10-31 Fri	41	—	unknown	18:55–23:20 (marginal, 4.42 h)	79.1° 23:15	10.46	97%	31.1°
2031-11-01 Sat	57	—	unknown	18:20–04:20 (marginal, 10.0 h)	79.1° 23:15	10.49	93%	41.9°
2031-11-02 Sun	91	—	unknown	18:50–22:15 (good, 3.42 h)	79.1° 23:10	10.53	87%	53.1°
2031-11-03 Mon	98	—	unknown	18:50–01:30 (good, 6.67 h)	79.1° 23:05	10.57	80%	64.5°
2031-11-04 Tue	100	—	unknown	18:50–03:05 (good, 8.25 h)	79.1° 23:00	10.6	72%	75.8°
2031-11-05 Wed	100	—	unknown	18:50–04:05 (good, 9.25 h)	79.1° 22:55	10.64	63%	87.0°
2031-11-06 Thu	100	—	unknown	18:45–04:10 (good, 9.42 h)	79.1° 22:55	10.67	54%	98.3°
2031-11-07 Fri	100	—	unknown	18:45–04:15 (good, 9.5 h)	79.1° 22:50	10.7	44%	109.6°
2031-11-08 Sat	100	—	unknown	18:45–04:15 (good, 9.5 h)	79.1° 22:45	10.74	35%	120.9°
2031-11-09 Sun	100	—	unknown	18:45–04:10 (good, 9.42 h)	79.1° 22:40	10.77	26%	132.2°
2031-11-10 Mon	100	—	unknown	18:45–04:10 (good, 9.42 h)	79.1° 22:35	10.8	17%	143.3°
2031-11-11 Tue	100	—	unknown	18:45–04:05 (good, 9.33 h)	79.1° 22:35	10.83	10%	153.7°
2031-11-12 Wed	100	—	unknown	18:40–04:00 (good, 9.33 h)	79.1° 22:30	10.86	5%	161.1°
2031-11-13 Thu	100	—	unknown	18:40–04:00 (good, 9.33 h)	79.1° 22:25	10.89	1%	160.8°
2031-11-14 Fri	100	—	unknown	18:40–03:55 (good, 9.25 h)	79.1° 22:20	10.92	0%	152.5°
2031-11-15 Sat	100	—	unknown	18:40–03:50 (good, 9.17 h)	79.1° 22:20	10.95	1%	140.7°
2031-11-16 Sun	100	—	unknown	18:40–03:45 (good, 9.08 h)	79.1° 22:15	10.98	6%	127.7°
2031-11-17 Mon	100	—	unknown	18:40–03:40 (good, 9.0 h)	79.1° 22:10	11.01	12%	114.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-10-19&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.