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: 08-01 (100), 08-02 (100), 08-03 (100), 08-04 (100), 08-05 (100) — by astronomy; check the weather when the night is within four days.

2044-07-20astronomy score per night — click a bar for that night2044-08-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-07-20 Wed	58	—	unknown	01:30–04:10 (good, 2.67 h)	79.2° 07:00	5.26	20%	34.7°
2044-07-21 Thu	67	—	unknown	01:30–04:10 (good, 2.67 h)	79.2° 06:55	5.3	12%	48.1°
2044-07-22 Fri	74	—	unknown	01:25–04:10 (good, 2.75 h)	79.2° 06:50	5.35	5%	62.3°
2044-07-23 Sat	78	—	unknown	01:20–04:10 (good, 2.83 h)	79.2° 06:45	5.4	1%	76.8°
2044-07-24 Sun	81	—	unknown	01:15–04:15 (good, 3.0 h)	79.2° 06:45	5.45	0%	91.4°
2044-07-25 Mon	83	—	unknown	01:10–04:15 (good, 3.08 h)	79.2° 06:40	5.51	2%	105.7°
2044-07-26 Tue	85	—	unknown	01:10–04:15 (good, 3.08 h)	79.2° 06:35	5.56	7%	119.7°
2044-07-27 Wed	89	—	unknown	01:05–04:20 (good, 3.25 h)	79.2° 06:30	5.61	14%	133.1°
2044-07-28 Thu	91	—	unknown	01:00–04:20 (good, 3.33 h)	79.2° 06:30	5.67	22%	145.7°
2044-07-29 Fri	93	—	unknown	00:55–04:20 (good, 3.42 h)	79.2° 06:25	5.72	32%	156.7°
2044-07-30 Sat	95	—	unknown	00:50–04:25 (good, 3.58 h)	79.2° 06:20	5.77	42%	164.0°
2044-07-31 Sun	97	—	unknown	00:50–04:25 (good, 3.58 h)	79.2° 06:15	5.83	52%	163.1°
2044-08-01 Mon	100	—	unknown	00:45–04:25 (good, 3.67 h)	79.2° 06:10	5.88	62%	155.3°
2044-08-02 Tue	100	—	unknown	00:45–04:30 (good, 3.75 h)	79.2° 06:10	5.94	71%	145.2°
2044-08-03 Wed	100	—	unknown	00:45–04:30 (good, 3.75 h)	79.2° 06:05	5.99	79%	134.3°
2044-08-04 Thu	100	—	unknown	00:40–04:30 (good, 3.83 h)	79.2° 06:00	6.05	86%	123.2°
2044-08-05 Fri	100	—	unknown	00:40–04:35 (good, 3.92 h)	79.2° 05:55	6.11	92%	111.9°
2044-08-06 Sat	94	—	unknown	00:45–04:35 (good, 3.83 h)	79.2° 05:50	6.16	96%	100.5°
2044-08-07 Sun	67	—	unknown	01:05–04:35 (good, 3.5 h)	79.2° 05:50	6.22	99%	88.9°
2044-08-08 Mon	54	—	unknown	02:20–04:40 (good, 2.33 h)	79.2° 05:45	6.28	100%	77.2°
2044-08-09 Tue	42	—	unknown	04:25–04:40 (good, 0.25 h)	79.2° 05:40	6.33	99%	65.4°
2044-08-10 Wed	32	—	unknown	00:00–04:40 (marginal, 4.67 h)	79.2° 05:35	6.39	96%	53.6°
2044-08-11 Thu	25	—	unknown	00:00–04:40 (marginal, 4.67 h)	79.2° 05:35	6.45	91%	41.8°
2044-08-12 Fri	22	—	unknown	23:55–04:45 (marginal, 4.83 h)	79.2° 05:30	6.51	84%	30.3°
2044-08-13 Sat	29	—	unknown	23:40–04:45 (marginal, 5.08 h)	79.2° 05:25	6.56	76%	20.2°
2044-08-14 Sun	40	—	unknown	23:30–04:45 (marginal, 5.25 h)	79.2° 05:20	6.62	66%	15.2°
2044-08-15 Mon	55	—	unknown	00:40–04:20 (good, 3.67 h)	79.2° 05:15	6.68	55%	20.1°
2044-08-16 Tue	73	—	unknown	00:05–04:50 (good, 4.75 h)	79.2° 05:15	6.74	44%	30.9°
2044-08-17 Wed	84	—	unknown	23:40–04:50 (good, 5.17 h)	79.2° 05:10	6.79	33%	43.6°
2044-08-18 Thu	92	—	unknown	23:40–04:55 (good, 5.25 h)	79.2° 05:05	6.85	22%	57.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-07-20&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.