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: 08-22 (100), 08-23 (100), 08-24 (100), 08-25 (100), 08-26 (100) — by astronomy; check the weather when the night is within four days.

2041-08-10astronomy score per night — click a bar for that night2041-09-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-08-10 Sat	77	—	unknown	00:35–04:40 (good, 4.08 h)	79.2° 05:35	6.38	98%	92.6°
2041-08-11 Sun	59	—	unknown	01:55–04:40 (good, 2.75 h)	79.2° 05:35	6.43	100%	78.4°
2041-08-12 Mon	44	—	unknown	04:25–04:45 (good, 0.33 h)	79.2° 05:30	6.49	99%	64.2°
2041-08-13 Tue	33	—	unknown	23:45–04:45 (marginal, 5.0 h)	79.2° 05:25	6.55	95%	50.3°
2041-08-14 Wed	27	—	unknown	23:45–04:45 (marginal, 5.0 h)	79.2° 05:20	6.61	88%	37.3°
2041-08-15 Thu	30	—	unknown	23:35–04:50 (marginal, 5.25 h)	79.2° 05:20	6.66	79%	26.3°
2041-08-16 Fri	40	—	unknown	23:20–04:50 (marginal, 5.5 h)	79.2° 05:15	6.72	69%	20.1°
2041-08-17 Sat	54	—	unknown	00:55–03:35 (good, 2.67 h)	79.2° 05:10	6.78	59%	22.3°
2041-08-18 Sun	73	—	unknown	23:40–04:55 (good, 5.25 h)	79.2° 05:05	6.84	48%	30.6°
2041-08-19 Mon	84	—	unknown	23:35–04:55 (good, 5.33 h)	79.2° 05:00	6.89	38%	41.1°
2041-08-20 Tue	90	—	unknown	23:30–04:55 (good, 5.42 h)	79.2° 05:00	6.95	28%	52.3°
2041-08-21 Wed	96	—	unknown	23:25–04:55 (good, 5.5 h)	79.2° 04:55	7.01	20%	63.6°
2041-08-22 Thu	100	—	unknown	23:25–05:00 (good, 5.58 h)	79.2° 04:50	7.07	12%	75.0°
2041-08-23 Fri	100	—	unknown	23:20–05:00 (good, 5.67 h)	79.2° 04:45	7.12	7%	86.3°
2041-08-24 Sat	100	—	unknown	23:15–05:00 (good, 5.75 h)	79.2° 04:40	7.18	3%	97.5°
2041-08-25 Sun	100	—	unknown	23:10–05:05 (good, 5.92 h)	79.2° 04:40	7.24	1%	108.7°
2041-08-26 Mon	100	—	unknown	23:05–05:05 (good, 6.0 h)	79.2° 04:35	7.29	0%	119.6°
2041-08-27 Tue	100	—	unknown	23:05–05:05 (good, 6.0 h)	79.2° 04:30	7.35	2%	130.4°
2041-08-28 Wed	100	—	unknown	23:00–05:05 (good, 6.08 h)	79.2° 04:25	7.41	5%	140.8°
2041-08-29 Thu	100	—	unknown	22:55–05:10 (good, 6.25 h)	79.2° 04:25	7.46	9%	150.3°
2041-08-30 Fri	100	—	unknown	22:50–05:10 (good, 6.33 h)	79.2° 04:20	7.52	16%	157.7°
2041-08-31 Sat	100	—	unknown	22:45–05:10 (good, 6.42 h)	79.2° 04:15	7.58	23%	160.3°
2041-09-01 Sun	100	—	unknown	22:45–05:15 (good, 6.5 h)	79.2° 04:10	7.63	32%	156.1°
2041-09-02 Mon	100	—	unknown	22:45–05:15 (good, 6.5 h)	79.2° 04:05	7.69	42%	147.5°
2041-09-03 Tue	100	—	unknown	22:40–05:15 (good, 6.58 h)	79.2° 04:05	7.74	52%	136.7°
2041-09-04 Wed	100	—	unknown	22:35–05:15 (good, 6.67 h)	79.2° 04:00	7.8	63%	124.7°
2041-09-05 Thu	100	—	unknown	22:35–05:20 (good, 6.75 h)	79.2° 03:55	7.85	73%	112.0°
2041-09-06 Fri	100	—	unknown	22:40–05:20 (good, 6.67 h)	79.2° 03:50	7.91	83%	98.6°
2041-09-07 Sat	100	—	unknown	23:00–05:20 (good, 6.33 h)	79.2° 03:45	7.96	91%	84.8°
2041-09-08 Sun	100	—	unknown	00:45–05:20 (good, 4.58 h)	79.2° 03:45	8.02	96%	70.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-08-10&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.