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: 03-17 (3), 03-18 (3), 03-19 (2), 03-20 (1), 03-21 (1) — by astronomy; check the weather when the night is within four days.

2044-03-17astronomy score per night — click a bar for that night2044-04-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-03-17 Thu	3	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.2° 14:15	8.84	83%	160.2°
2044-03-18 Fri	3	—	unknown	19:35–19:45 (marginal, 0.17 h)	79.2° 14:10	8.79	75%	151.3°
2044-03-19 Sat	2	—	unknown	19:35–19:40 (marginal, 0.08 h)	79.2° 14:05	8.74	66%	140.9°
2044-03-20 Sun	1	—	unknown	—	79.2° 14:05	8.69	57%	129.9°
2044-03-21 Mon	1	—	unknown	—	79.2° 14:00	8.64	48%	118.8°
2044-03-22 Tue	1	—	unknown	—	79.2° 13:55	8.58	38%	107.4°
2044-03-23 Wed	1	—	unknown	—	79.2° 13:50	8.53	29%	95.8°
2044-03-24 Thu	0	—	unknown	—	79.2° 13:45	8.48	21%	84.0°
2044-03-25 Fri	0	—	unknown	—	79.2° 13:45	8.43	13%	71.9°
2044-03-26 Sat	0	—	unknown	—	79.2° 13:40	8.37	7%	59.6°
2044-03-27 Sun	0	—	unknown	—	79.2° 14:35	8.32	3%	47.1°
2044-03-28 Mon	0	—	unknown	—	79.2° 14:30	8.27	0%	34.7°
2044-03-29 Tue	0	—	unknown	—	79.2° 14:25	8.21	0%	23.3°
2044-03-30 Wed	0	—	unknown	—	79.2° 14:25	8.16	3%	16.1°
2044-03-31 Thu	0	—	unknown	—	79.2° 14:20	8.1	8%	19.2°
2044-04-01 Fri	0	—	unknown	—	79.2° 14:15	8.05	16%	29.6°
2044-04-02 Sat	0	—	unknown	—	79.2° 14:10	7.99	25%	42.3°
2044-04-03 Sun	0	—	unknown	—	79.2° 14:10	7.94	36%	55.7°
2044-04-04 Mon	0	—	unknown	—	79.2° 14:05	7.88	47%	69.2°
2044-04-05 Tue	0	—	unknown	—	79.2° 14:00	7.83	59%	82.6°
2044-04-06 Wed	0	—	unknown	—	79.2° 13:55	7.77	70%	96.0°
2044-04-07 Thu	0	—	unknown	—	79.2° 13:50	7.71	79%	109.2°
2044-04-08 Fri	0	—	unknown	—	79.2° 13:50	7.66	87%	122.0°
2044-04-09 Sat	0	—	unknown	—	79.2° 13:45	7.6	94%	134.5°
2044-04-10 Sun	0	—	unknown	—	79.2° 13:40	7.54	98%	146.4°
2044-04-11 Mon	0	—	unknown	—	79.2° 13:35	7.49	100%	156.8°
2044-04-12 Tue	0	—	unknown	—	79.2° 13:30	7.43	100%	163.6°
2044-04-13 Wed	0	—	unknown	—	79.2° 13:30	7.37	98%	162.4°
2044-04-14 Thu	0	—	unknown	—	79.2° 13:25	7.31	94%	154.6°
2044-04-15 Fri	0	—	unknown	—	79.2° 13:20	7.26	88%	144.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-03-17&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.