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: 03-16 (5), 03-17 (4), 03-18 (3), 03-19 (2), 03-20 (1) — by astronomy; check the weather when the night is within four days.

2047-03-16astronomy score per night — click a bar for that night2047-04-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-03-16 Sat	5	—	unknown	20:05–20:25 (marginal, 0.33 h)	79.2° 14:20	8.93	69%	146.3°
2047-03-17 Sun	4	—	unknown	19:30–19:50 (marginal, 0.33 h)	79.2° 14:20	8.88	58%	133.4°
2047-03-18 Mon	3	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.2° 14:15	8.83	47%	120.5°
2047-03-19 Tue	2	—	unknown	19:35–19:40 (marginal, 0.08 h)	79.2° 14:10	8.78	37%	107.7°
2047-03-20 Wed	1	—	unknown	19:35–19:40 (marginal, 0.08 h)	79.2° 14:05	8.73	27%	95.2°
2047-03-21 Thu	1	—	unknown	—	79.2° 14:00	8.67	18%	82.9°
2047-03-22 Fri	1	—	unknown	—	79.2° 14:00	8.62	12%	70.9°
2047-03-23 Sat	1	—	unknown	—	79.2° 13:55	8.57	6%	59.0°
2047-03-24 Sun	0	—	unknown	—	79.2° 13:50	8.52	2%	47.5°
2047-03-25 Mon	0	—	unknown	—	79.2° 13:45	8.46	0%	36.4°
2047-03-26 Tue	0	—	unknown	—	79.2° 13:40	8.41	0%	26.0°
2047-03-27 Wed	0	—	unknown	—	79.2° 13:40	8.36	2%	17.5°
2047-03-28 Thu	0	—	unknown	—	79.2° 13:35	8.3	6%	14.6°
2047-03-29 Fri	0	—	unknown	—	79.2° 13:30	8.25	10%	19.8°
2047-03-30 Sat	0	—	unknown	—	79.2° 13:25	8.2	17%	29.1°
2047-03-31 Sun	0	—	unknown	—	79.2° 14:25	8.14	25%	39.8°
2047-04-01 Mon	0	—	unknown	—	79.2° 14:20	8.09	33%	51.1°
2047-04-02 Tue	0	—	unknown	—	79.2° 14:15	8.03	43%	62.9°
2047-04-03 Wed	0	—	unknown	—	79.2° 14:10	7.98	53%	75.2°
2047-04-04 Thu	0	—	unknown	—	79.2° 14:05	7.92	63%	87.8°
2047-04-05 Fri	0	—	unknown	—	79.2° 14:05	7.87	74%	100.9°
2047-04-06 Sat	0	—	unknown	—	79.2° 14:00	7.81	83%	114.4°
2047-04-07 Sun	0	—	unknown	—	79.2° 13:55	7.75	91%	128.3°
2047-04-08 Mon	0	—	unknown	—	79.2° 13:50	7.7	96%	142.2°
2047-04-09 Tue	0	—	unknown	—	79.2° 13:45	7.64	99%	155.3°
2047-04-10 Wed	0	—	unknown	—	79.2° 13:45	7.58	99%	164.7°
2047-04-11 Thu	0	—	unknown	—	79.2° 13:40	7.53	96%	162.3°
2047-04-12 Fri	0	—	unknown	—	79.2° 13:35	7.47	91%	151.0°
2047-04-13 Sat	0	—	unknown	—	79.2° 13:30	7.41	83%	137.9°
2047-04-14 Sun	0	—	unknown	—	79.2° 13:25	7.36	73%	124.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-03-16&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.