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: 05-31 (1), 06-01 (1), 06-02 (1) — by astronomy; check the weather when the night is within four days.

2046-05-04astronomy score per night — click a bar for that night2046-06-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-05-04 Fri	0	—	unknown	—	79.2° 12:10	6.18	2%	14.6°
2046-05-05 Sat	0	—	unknown	—	79.2° 12:00	6.12	0%	17.4°
2046-05-06 Sun	0	—	unknown	—	79.2° 12:00	6.07	1%	26.5°
2046-05-07 Mon	0	—	unknown	—	79.2° 11:50	6.01	4%	37.8°
2046-05-08 Tue	0	—	unknown	—	79.2° 11:50	5.95	8%	49.9°
2046-05-09 Wed	0	—	unknown	—	79.2° 11:45	5.9	15%	62.5°
2046-05-10 Thu	0	—	unknown	—	79.2° 11:40	5.84	24%	75.5°
2046-05-11 Fri	0	—	unknown	—	79.2° 11:35	5.79	33%	88.7°
2046-05-12 Sat	0	—	unknown	—	79.2° 11:30	5.73	44%	102.1°
2046-05-13 Sun	0	—	unknown	—	79.2° 11:30	5.68	56%	115.6°
2046-05-14 Mon	0	—	unknown	—	79.2° 11:25	5.62	67%	129.2°
2046-05-15 Tue	0	—	unknown	—	79.2° 11:20	5.57	77%	142.7°
2046-05-16 Wed	0	—	unknown	—	79.2° 11:15	5.52	86%	155.3°
2046-05-17 Thu	0	—	unknown	—	79.2° 11:15	5.46	93%	164.5°
2046-05-18 Fri	0	—	unknown	—	79.2° 11:10	5.41	98%	163.3°
2046-05-19 Sat	0	—	unknown	—	79.2° 11:05	5.36	100%	153.1°
2046-05-20 Sun	0	—	unknown	—	79.2° 11:00	5.31	99%	140.7°
2046-05-21 Mon	0	—	unknown	—	79.2° 10:55	5.26	96%	127.8°
2046-05-22 Tue	0	—	unknown	—	79.2° 10:55	5.21	91%	115.1°
2046-05-23 Wed	0	—	unknown	—	79.2° 10:50	5.17	84%	102.6°
2046-05-24 Thu	0	—	unknown	—	79.2° 10:45	5.12	76%	90.4°
2046-05-25 Fri	0	—	unknown	—	79.2° 10:40	5.07	67%	78.4°
2046-05-26 Sat	0	—	unknown	—	79.2° 10:35	5.03	57%	66.8°
2046-05-27 Sun	0	—	unknown	—	79.2° 10:35	4.99	48%	55.3°
2046-05-28 Mon	0	—	unknown	—	79.2° 10:30	4.94	39%	44.1°
2046-05-29 Tue	0	—	unknown	—	79.2° 10:25	4.9	30%	33.3°
2046-05-30 Wed	0	—	unknown	—	79.2° 10:20	4.86	21%	23.2°
2046-05-31 Thu	1	—	unknown	—	79.2° 10:20	4.83	14%	15.6°
2046-06-01 Fri	1	—	unknown	—	79.2° 10:15	4.79	8%	15.5°
2046-06-02 Sat	1	—	unknown	—	79.2° 10:10	4.75	3%	23.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-05-04&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.