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: 03-13 (5), 03-14 (4), 03-15 (3), 03-16 (2), 03-17 (2) — by astronomy; check the weather when the night is within four days.

2046-03-13astronomy score per night — click a bar for that night2046-04-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-03-13 Tue	5	—	unknown	20:00–20:35 (marginal, 0.58 h)	79.2° 14:30	9.07	32%	31.7°
2046-03-14 Wed	4	—	unknown	20:00–20:30 (marginal, 0.5 h)	79.2° 14:30	9.02	42%	43.4°
2046-03-15 Thu	3	—	unknown	20:05–20:20 (marginal, 0.25 h)	79.2° 14:25	8.97	52%	55.8°
2046-03-16 Fri	2	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.2° 14:20	8.92	63%	68.8°
2046-03-17 Sat	2	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.2° 14:15	8.87	74%	82.3°
2046-03-18 Sun	2	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.2° 14:15	8.82	83%	96.3°
2046-03-19 Mon	1	—	unknown	—	79.2° 14:10	8.77	91%	110.6°
2046-03-20 Tue	1	—	unknown	—	79.2° 14:05	8.71	97%	125.1°
2046-03-21 Wed	1	—	unknown	—	79.2° 14:00	8.66	100%	139.4°
2046-03-22 Thu	1	—	unknown	—	79.2° 13:55	8.61	99%	153.0°
2046-03-23 Fri	1	—	unknown	—	79.2° 13:55	8.56	96%	163.6°
2046-03-24 Sat	0	—	unknown	—	79.2° 13:50	8.5	90%	164.3°
2046-03-25 Sun	0	—	unknown	—	79.2° 14:45	8.45	83%	155.0°
2046-03-26 Mon	0	—	unknown	—	79.2° 14:40	8.4	74%	143.0°
2046-03-27 Tue	0	—	unknown	—	79.2° 14:35	8.35	64%	130.6°
2046-03-28 Wed	0	—	unknown	—	79.2° 14:35	8.29	54%	118.3°
2046-03-29 Thu	0	—	unknown	—	79.2° 14:30	8.24	44%	106.3°
2046-03-30 Fri	0	—	unknown	—	79.2° 14:25	8.18	34%	94.4°
2046-03-31 Sat	0	—	unknown	—	79.2° 14:20	8.13	25%	82.8°
2046-04-01 Sun	0	—	unknown	—	79.2° 14:20	8.07	18%	71.3°
2046-04-02 Mon	0	—	unknown	—	79.2° 14:15	8.02	11%	59.9°
2046-04-03 Tue	0	—	unknown	—	79.2° 14:10	7.96	6%	48.7°
2046-04-04 Wed	0	—	unknown	—	79.2° 14:05	7.91	2%	37.7°
2046-04-05 Thu	0	—	unknown	—	79.2° 14:00	7.85	0%	27.1°
2046-04-06 Fri	0	—	unknown	—	79.2° 14:00	7.8	0%	18.2°
2046-04-07 Sat	0	—	unknown	—	79.2° 13:55	7.74	2%	14.4°
2046-04-08 Sun	0	—	unknown	—	79.2° 13:50	7.68	6%	19.4°
2046-04-09 Mon	0	—	unknown	—	79.2° 13:45	7.63	11%	29.2°
2046-04-10 Tue	0	—	unknown	—	79.2° 13:40	7.57	18%	40.6°
2046-04-11 Wed	0	—	unknown	—	79.2° 13:40	7.51	27%	52.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-03-13&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.