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: 08-02 (100), 08-03 (100), 08-04 (100), 08-05 (100), 08-06 (100) — by astronomy; check the weather when the night is within four days.

2041-07-10astronomy score per night — click a bar for that night2041-08-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-07-10 Wed	45	—	unknown	02:20–03:55 (good, 1.58 h)	79.2° 07:40	4.81	89%	139.6°
2041-07-11 Thu	45	—	unknown	02:15–03:55 (good, 1.67 h)	79.2° 07:35	4.85	95%	127.3°
2041-07-12 Fri	40	—	unknown	02:15–03:55 (good, 1.67 h)	79.2° 07:30	4.89	99%	114.1°
2041-07-13 Sat	34	—	unknown	02:20–03:55 (good, 1.58 h)	79.2° 07:30	4.93	100%	100.4°
2041-07-14 Sun	29	—	unknown	02:50–04:00 (good, 1.17 h)	79.2° 07:25	4.97	98%	86.4°
2041-07-15 Mon	25	—	unknown	03:55–04:00 (good, 0.08 h)	79.2° 07:20	5.01	93%	72.4°
2041-07-16 Tue	22	—	unknown	01:30–04:00 (marginal, 2.5 h)	79.2° 07:15	5.06	86%	58.6°
2041-07-17 Wed	21	—	unknown	01:25–04:05 (marginal, 2.67 h)	79.2° 07:10	5.1	77%	45.5°
2041-07-18 Thu	23	—	unknown	01:15–04:05 (marginal, 2.83 h)	79.2° 07:10	5.15	66%	33.4°
2041-07-19 Fri	29	—	unknown	03:30–04:05 (good, 0.58 h)	79.2° 07:05	5.19	55%	23.9°
2041-07-20 Sat	38	—	unknown	01:55–04:05 (good, 2.17 h)	79.2° 07:00	5.24	44%	20.1°
2041-07-21 Sun	48	—	unknown	01:45–04:10 (good, 2.42 h)	79.2° 06:55	5.29	34%	24.2°
2041-07-22 Mon	59	—	unknown	01:25–04:10 (good, 2.75 h)	79.2° 06:50	5.34	24%	33.1°
2041-07-23 Tue	69	—	unknown	01:20–04:10 (good, 2.83 h)	79.2° 06:50	5.39	16%	43.8°
2041-07-24 Wed	76	—	unknown	01:15–04:15 (good, 3.0 h)	79.2° 06:45	5.44	9%	55.0°
2041-07-25 Thu	82	—	unknown	01:15–04:15 (good, 3.0 h)	79.2° 06:40	5.49	4%	66.4°
2041-07-26 Fri	84	—	unknown	01:10–04:15 (good, 3.08 h)	79.2° 06:35	5.54	1%	77.8°
2041-07-27 Sat	89	—	unknown	01:05–04:20 (good, 3.25 h)	79.2° 06:35	5.6	0%	89.1°
2041-07-28 Sun	91	—	unknown	01:00–04:20 (good, 3.33 h)	79.2° 06:30	5.65	1%	100.4°
2041-07-29 Mon	92	—	unknown	00:55–04:20 (good, 3.42 h)	79.2° 06:25	5.7	3%	111.5°
2041-07-30 Tue	95	—	unknown	00:55–04:25 (good, 3.5 h)	79.2° 06:20	5.76	8%	122.4°
2041-07-31 Wed	97	—	unknown	00:50–04:25 (good, 3.58 h)	79.2° 06:15	5.81	13%	133.0°
2041-08-01 Thu	99	—	unknown	00:45–04:25 (good, 3.67 h)	79.2° 06:15	5.87	20%	143.2°
2041-08-02 Fri	100	—	unknown	00:40–04:30 (good, 3.83 h)	79.2° 06:10	5.92	28%	152.3°
2041-08-03 Sat	100	—	unknown	00:40–04:30 (good, 3.83 h)	79.2° 06:05	5.98	38%	158.8°
2041-08-04 Sun	100	—	unknown	00:35–04:30 (good, 3.92 h)	79.2° 06:00	6.03	47%	159.5°
2041-08-05 Mon	100	—	unknown	00:30–04:30 (good, 4.0 h)	79.2° 05:55	6.09	57%	153.7°
2041-08-06 Tue	100	—	unknown	00:30–04:35 (good, 4.08 h)	79.2° 05:55	6.15	68%	144.1°
2041-08-07 Wed	100	—	unknown	00:30–04:35 (good, 4.08 h)	79.2° 05:50	6.2	77%	132.5°
2041-08-08 Thu	100	—	unknown	00:25–04:35 (good, 4.17 h)	79.2° 05:45	6.26	86%	119.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-07-10&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.