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: 08-08 (100), 08-09 (100), 08-10 (100), 08-11 (100), 08-12 (100) — by astronomy; check the weather when the night is within four days.

2037-07-22astronomy score per night — click a bar for that night2037-08-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-07-22 Wed	72	—	unknown	01:30–04:10 (good, 2.67 h)	79.2° 06:50	5.34	82%	136.5°
2037-07-23 Thu	73	—	unknown	01:30–04:10 (good, 2.67 h)	79.2° 06:50	5.39	90%	125.7°
2037-07-24 Fri	65	—	unknown	01:30–04:15 (good, 2.75 h)	79.2° 06:45	5.44	95%	114.4°
2037-07-25 Sat	57	—	unknown	01:35–04:15 (good, 2.67 h)	79.2° 06:40	5.49	98%	103.0°
2037-07-26 Sun	49	—	unknown	01:50–04:15 (good, 2.42 h)	79.2° 06:35	5.54	100%	91.7°
2037-07-27 Mon	42	—	unknown	02:45–04:20 (good, 1.58 h)	79.1° 06:30	5.6	99%	80.5°
2037-07-28 Tue	35	—	unknown	03:50–04:20 (good, 0.5 h)	79.2° 06:30	5.65	97%	69.6°
2037-07-29 Wed	30	—	unknown	00:40–04:20 (marginal, 3.67 h)	79.2° 06:25	5.7	93%	59.0°
2037-07-30 Thu	27	—	unknown	00:35–04:25 (marginal, 3.83 h)	79.2° 06:20	5.76	87%	48.8°
2037-07-31 Fri	27	—	unknown	00:30–04:25 (marginal, 3.92 h)	79.2° 06:15	5.81	80%	39.4°
2037-08-01 Sat	29	—	unknown	00:25–04:25 (marginal, 4.0 h)	79.1° 06:15	5.87	72%	31.3°
2037-08-02 Sun	37	—	unknown	00:15–04:30 (marginal, 4.25 h)	79.2° 06:10	5.92	63%	25.8°
2037-08-03 Mon	48	—	unknown	01:05–04:30 (good, 3.42 h)	79.2° 06:05	5.98	54%	24.9°
2037-08-04 Tue	64	—	unknown	00:35–04:30 (good, 3.92 h)	79.2° 06:00	6.03	44%	29.3°
2037-08-05 Wed	79	—	unknown	00:30–04:30 (good, 4.0 h)	79.2° 05:55	6.09	34%	37.3°
2037-08-06 Thu	90	—	unknown	00:25–04:35 (good, 4.17 h)	79.2° 05:55	6.15	25%	47.4°
2037-08-07 Fri	96	—	unknown	00:20–04:35 (good, 4.25 h)	79.2° 05:50	6.2	16%	58.9°
2037-08-08 Sat	100	—	unknown	00:20–04:35 (good, 4.25 h)	79.2° 05:45	6.26	9%	71.2°
2037-08-09 Sun	100	—	unknown	00:15–04:40 (good, 4.42 h)	79.2° 05:40	6.32	3%	84.1°
2037-08-10 Mon	100	—	unknown	00:10–04:40 (good, 4.5 h)	79.1° 05:35	6.37	0%	97.4°
2037-08-11 Tue	100	—	unknown	00:05–04:40 (good, 4.58 h)	79.2° 05:35	6.43	0%	110.9°
2037-08-12 Wed	100	—	unknown	00:00–04:45 (good, 4.75 h)	79.2° 05:30	6.49	3%	124.2°
2037-08-13 Thu	100	—	unknown	00:00–04:45 (good, 4.75 h)	79.2° 05:25	6.55	9%	136.7°
2037-08-14 Fri	100	—	unknown	23:55–04:45 (good, 4.83 h)	79.2° 05:20	6.6	17%	147.4°
2037-08-15 Sat	100	—	unknown	23:50–04:50 (good, 5.0 h)	79.1° 05:20	6.66	27%	154.4°
2037-08-16 Sun	100	—	unknown	23:45–04:50 (good, 5.08 h)	79.2° 05:15	6.72	38%	154.6°
2037-08-17 Mon	100	—	unknown	23:45–04:50 (good, 5.08 h)	79.2° 05:10	6.78	49%	148.4°
2037-08-18 Tue	100	—	unknown	23:45–04:55 (good, 5.17 h)	79.2° 05:05	6.83	60%	139.0°
2037-08-19 Wed	100	—	unknown	23:40–04:55 (good, 5.25 h)	79.2° 05:00	6.89	70%	128.3°
2037-08-20 Thu	100	—	unknown	23:40–04:55 (good, 5.25 h)	79.2° 05:00	6.95	79%	117.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-07-22&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.