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: 03-15 (3), 03-16 (3), 03-17 (3), 03-18 (2), 03-19 (1) — by astronomy; check the weather when the night is within four days.

2030-03-15astronomy score per night — click a bar for that night2030-04-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-03-15 Fri	3	—	unknown	20:05–20:25 (marginal, 0.33 h)	79.1° 14:25	8.97	83%	94.0°
2030-03-16 Sat	3	—	unknown	20:05–20:20 (marginal, 0.25 h)	79.1° 14:20	8.92	90%	106.8°
2030-03-17 Sun	3	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.1° 14:15	8.87	96%	119.9°
2030-03-18 Mon	2	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.1° 14:10	8.82	99%	133.2°
2030-03-19 Tue	1	—	unknown	—	79.1° 14:10	8.77	100%	146.3°
2030-03-20 Wed	1	—	unknown	—	79.1° 14:05	8.72	98%	158.0°
2030-03-21 Thu	1	—	unknown	—	79.1° 14:00	8.67	93%	164.3°
2030-03-22 Fri	1	—	unknown	—	79.1° 13:55	8.62	86%	159.2°
2030-03-23 Sat	1	—	unknown	—	79.1° 13:55	8.56	77%	147.8°
2030-03-24 Sun	0	—	unknown	—	79.1° 13:50	8.51	66%	134.8°
2030-03-25 Mon	0	—	unknown	—	79.1° 13:45	8.46	55%	121.6°
2030-03-26 Tue	0	—	unknown	—	79.1° 13:40	8.41	44%	108.4°
2030-03-27 Wed	0	—	unknown	—	79.1° 13:35	8.35	34%	95.3°
2030-03-28 Thu	0	—	unknown	—	79.1° 13:35	8.3	24%	82.5°
2030-03-29 Fri	0	—	unknown	—	79.1° 13:30	8.24	16%	70.0°
2030-03-30 Sat	0	—	unknown	—	79.1° 13:25	8.19	9%	57.7°
2030-03-31 Sun	0	—	unknown	—	79.1° 14:20	8.14	4%	45.8°
2030-04-01 Mon	0	—	unknown	—	79.1° 14:15	8.08	1%	34.5°
2030-04-02 Tue	0	—	unknown	—	79.1° 14:15	8.03	0%	24.4°
2030-04-03 Wed	0	—	unknown	—	79.1° 14:10	7.97	1%	17.1°
2030-04-04 Thu	0	—	unknown	—	79.1° 14:05	7.91	4%	16.6°
2030-04-05 Fri	0	—	unknown	—	79.1° 14:00	7.86	8%	23.2°
2030-04-06 Sat	0	—	unknown	—	79.1° 13:55	7.8	14%	32.7°
2030-04-07 Sun	0	—	unknown	—	79.1° 13:55	7.75	21%	43.3°
2030-04-08 Mon	0	—	unknown	—	79.1° 13:50	7.69	29%	54.4°
2030-04-09 Tue	0	—	unknown	—	79.1° 13:45	7.63	38%	65.7°
2030-04-10 Wed	0	—	unknown	—	79.1° 13:40	7.58	48%	77.4°
2030-04-11 Thu	0	—	unknown	—	79.1° 13:40	7.52	58%	89.4°
2030-04-12 Fri	0	—	unknown	—	79.1° 13:35	7.46	68%	101.7°
2030-04-13 Sat	0	—	unknown	—	79.1° 13:30	7.41	77%	114.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-03-15&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.