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: 07-19 (65), 07-18 (63), 07-17 (60), 07-16 (58), 07-15 (53) — by astronomy; check the weather when the night is within four days.

2031-06-20astronomy score per night — click a bar for that night2031-07-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-06-20 Fri	12	—	unknown	03:30–03:40 (good, 0.17 h)	79.1° 09:00	4.42	1%	69.7°
2031-06-21 Sat	13	—	unknown	03:30–03:40 (good, 0.17 h)	79.1° 08:55	4.42	4%	80.9°
2031-06-22 Sun	15	—	unknown	03:25–03:40 (good, 0.25 h)	79.1° 08:50	4.42	8%	92.2°
2031-06-23 Mon	16	—	unknown	03:20–03:40 (good, 0.33 h)	79.1° 08:50	4.43	14%	103.6°
2031-06-24 Tue	17	—	unknown	03:15–03:40 (good, 0.42 h)	79.1° 08:45	4.43	21%	115.0°
2031-06-25 Wed	19	—	unknown	03:15–03:40 (good, 0.42 h)	79.1° 08:40	4.44	30%	126.3°
2031-06-26 Thu	22	—	unknown	03:10–03:40 (good, 0.5 h)	79.1° 08:35	4.45	39%	137.7°
2031-06-27 Fri	23	—	unknown	03:05–03:40 (good, 0.58 h)	79.1° 08:30	4.46	49%	148.6°
2031-06-28 Sat	25	—	unknown	03:00–03:40 (good, 0.67 h)	79.1° 08:30	4.48	60%	158.2°
2031-06-29 Sun	25	—	unknown	02:55–03:40 (good, 0.75 h)	79.1° 08:25	4.5	70%	162.8°
2031-06-30 Mon	28	—	unknown	02:55–03:45 (good, 0.83 h)	79.1° 08:20	4.51	80%	158.2°
2031-07-01 Tue	28	—	unknown	02:55–03:45 (good, 0.83 h)	79.1° 08:15	4.53	88%	147.4°
2031-07-02 Wed	26	—	unknown	02:55–03:45 (good, 0.83 h)	79.1° 08:15	4.56	95%	134.4°
2031-07-03 Thu	26	—	unknown	02:50–03:45 (good, 0.92 h)	79.1° 08:10	4.58	99%	120.5°
2031-07-04 Fri	23	—	unknown	02:55–03:45 (good, 0.83 h)	79.1° 08:05	4.6	100%	106.0°
2031-07-05 Sat	19	—	unknown	03:20–03:45 (good, 0.42 h)	79.1° 08:00	4.63	98%	91.5°
2031-07-06 Sun	16	—	unknown	02:10–03:50 (marginal, 1.67 h)	79.1° 07:55	4.66	93%	77.1°
2031-07-07 Mon	15	—	unknown	02:10–03:50 (marginal, 1.67 h)	79.1° 07:55	4.69	86%	63.1°
2031-07-08 Tue	14	—	unknown	02:05–03:50 (marginal, 1.75 h)	79.1° 07:50	4.72	77%	49.7°
2031-07-09 Wed	15	—	unknown	01:55–03:50 (marginal, 1.92 h)	79.1° 07:45	4.76	66%	37.2°
2031-07-10 Thu	19	—	unknown	01:50–03:55 (marginal, 2.08 h)	79.1° 07:40	4.79	56%	26.3°
2031-07-11 Fri	25	—	unknown	02:35–03:55 (good, 1.33 h)	79.1° 07:35	4.83	45%	18.6°
2031-07-12 Sat	32	—	unknown	02:25–03:55 (good, 1.5 h)	79.1° 07:35	4.87	36%	18.1°
2031-07-13 Sun	39	—	unknown	02:10–03:55 (good, 1.75 h)	79.1° 07:30	4.91	26%	24.7°
2031-07-14 Mon	47	—	unknown	02:00–04:00 (good, 2.0 h)	79.1° 07:25	4.95	18%	34.3°
2031-07-15 Tue	53	—	unknown	01:55–04:00 (good, 2.08 h)	79.1° 07:20	4.99	12%	44.8°
2031-07-16 Wed	58	—	unknown	01:50–04:00 (good, 2.17 h)	79.1° 07:15	5.03	6%	55.8°
2031-07-17 Thu	60	—	unknown	01:45–04:00 (good, 2.25 h)	79.1° 07:15	5.08	2%	66.9°
2031-07-18 Fri	63	—	unknown	01:40–04:05 (good, 2.42 h)	79.1° 07:10	5.12	0%	78.2°
2031-07-19 Sat	65	—	unknown	01:40–04:05 (good, 2.42 h)	79.1° 07:05	5.17	0%	89.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-06-20&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.