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: 11-18 (100), 11-19 (100), 11-20 (100), 11-21 (100), 11-22 (100) — by astronomy; check the weather when the night is within four days.

2035-11-18astronomy score per night — click a bar for that night2035-12-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-11-18 Sun	100	—	unknown	18:40–01:00 (good, 6.33 h)	79.1° 22:05	11.04	84%	72.0°
2035-11-19 Mon	100	—	unknown	18:35–02:40 (good, 8.08 h)	79.1° 22:00	11.06	75%	85.3°
2035-11-20 Tue	100	—	unknown	18:35–03:10 (good, 8.58 h)	79.1° 22:00	11.09	64%	98.5°
2035-11-21 Wed	100	—	unknown	18:35–03:15 (good, 8.67 h)	79.1° 21:55	11.11	53%	111.2°
2035-11-22 Thu	100	—	unknown	18:35–03:20 (good, 8.75 h)	79.1° 21:50	11.14	42%	123.4°
2035-11-23 Fri	100	—	unknown	18:35–03:15 (good, 8.67 h)	79.1° 21:45	11.16	32%	134.9°
2035-11-24 Sat	100	—	unknown	18:35–03:15 (good, 8.67 h)	79.1° 21:45	11.19	22%	145.1°
2035-11-25 Sun	100	—	unknown	18:35–03:10 (good, 8.58 h)	79.1° 21:40	11.21	15%	152.9°
2035-11-26 Mon	100	—	unknown	18:35–03:05 (good, 8.5 h)	79.1° 21:35	11.23	8%	156.2°
2035-11-27 Tue	100	—	unknown	18:35–03:05 (good, 8.5 h)	79.1° 21:30	11.25	4%	153.6°
2035-11-28 Wed	100	—	unknown	18:35–03:00 (good, 8.42 h)	79.1° 21:25	11.27	1%	146.6°
2035-11-29 Thu	100	—	unknown	18:35–02:55 (good, 8.33 h)	79.1° 21:25	11.29	0%	137.5°
2035-11-30 Fri	100	—	unknown	18:35–02:50 (good, 8.25 h)	79.1° 21:20	11.31	1%	127.4°
2035-12-01 Sat	100	—	unknown	18:35–02:45 (good, 8.17 h)	79.2° 21:15	11.33	4%	116.9°
2035-12-02 Sun	100	—	unknown	18:35–02:45 (good, 8.17 h)	79.1° 21:10	11.34	9%	106.3°
2035-12-03 Mon	100	—	unknown	18:35–02:40 (good, 8.08 h)	79.1° 21:05	11.36	15%	95.5°
2035-12-04 Tue	100	—	unknown	18:35–02:35 (good, 8.0 h)	79.1° 21:05	11.38	22%	84.7°
2035-12-05 Wed	100	—	unknown	18:35–02:30 (good, 7.92 h)	79.1° 21:00	11.39	30%	73.9°
2035-12-06 Thu	100	—	unknown	18:35–02:30 (good, 7.92 h)	79.2° 20:55	11.4	39%	63.1°
2035-12-07 Fri	95	—	unknown	18:35–02:25 (good, 7.83 h)	79.1° 20:50	11.42	49%	52.3°
2035-12-08 Sat	87	—	unknown	18:35–02:20 (good, 7.75 h)	79.1° 20:45	11.43	59%	41.9°
2035-12-09 Sun	77	—	unknown	01:50–02:15 (good, 0.42 h)	79.1° 20:45	11.44	69%	32.4°
2035-12-10 Mon	48	—	unknown	18:35–02:35 (marginal, 8.0 h)	79.2° 20:40	11.45	78%	25.5°
2035-12-11 Tue	34	—	unknown	18:35–02:15 (marginal, 7.67 h)	79.1° 20:35	11.46	87%	24.3°
2035-12-12 Wed	27	—	unknown	18:35–01:45 (marginal, 7.17 h)	79.1° 20:30	11.47	93%	30.2°
2035-12-13 Thu	35	—	unknown	18:35–00:05 (marginal, 5.5 h)	79.1° 20:30	11.48	98%	40.6°
2035-12-14 Fri	50	—	unknown	18:35–01:35 (marginal, 7.0 h)	79.1° 20:25	11.48	100%	53.1°
2035-12-15 Sat	70	—	unknown	18:35–20:45 (good, 2.17 h)	79.2° 20:20	11.49	99%	66.5°
2035-12-16 Sun	100	—	unknown	18:35–23:25 (good, 4.83 h)	79.1° 20:15	11.5	94%	80.2°
2035-12-17 Mon	100	—	unknown	18:35–01:00 (good, 6.42 h)	79.1° 20:10	11.5	88%	93.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-11-18&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.