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 Vega: 07-23 (100), 07-24 (100), 07-25 (100), 07-26 (100), 07-27 (100) — by astronomy; check the weather when the night is within four days.

2046-07-21astronomy score per night — click a bar for that night2046-08-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-07-21 Sat	77	—	unknown	22:50–03:30 (good, 4.67 h)	87.1° 00:00	5.28	86%	72.4°
2046-07-22 Sun	82	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:55	5.33	79%	77.0°
2046-07-23 Mon	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:55	5.38	70%	81.9°
2046-07-24 Tue	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:50	5.43	62%	87.2°
2046-07-25 Wed	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:45	5.48	52%	92.6°
2046-07-26 Thu	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:40	5.53	42%	98.0°
2046-07-27 Fri	100	—	unknown	22:45–04:20 (good, 5.58 h)	87.1° 23:35	5.59	33%	103.2°
2046-07-28 Sat	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:35	5.64	23%	108.0°
2046-07-29 Sun	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:30	5.69	15%	112.1°
2046-07-30 Mon	100	—	unknown	22:40–04:25 (good, 5.75 h)	87.1° 23:25	5.75	8%	115.1°
2046-07-31 Tue	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:20	5.8	3%	116.8°
2046-08-01 Wed	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:15	5.86	0%	116.7°
2046-08-02 Thu	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:15	5.91	0%	114.7°
2046-08-03 Fri	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:10	5.97	3%	111.1°
2046-08-04 Sat	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:05	6.02	9%	106.1°
2046-08-05 Sun	100	—	unknown	22:25–04:30 (good, 6.08 h)	87.1° 23:00	6.08	17%	100.2°
2046-08-06 Mon	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.14	27%	93.8°
2046-08-07 Tue	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.19	37%	87.3°
2046-08-08 Wed	100	—	unknown	22:20–04:35 (good, 6.25 h)	87.1° 22:50	6.25	49%	81.1°
2046-08-09 Thu	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:45	6.31	60%	75.5°
2046-08-10 Fri	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:40	6.36	70%	70.6°
2046-08-11 Sat	96	—	unknown	22:15–04:35 (good, 6.33 h)	87.1° 22:40	6.42	79%	66.8°
2046-08-12 Sun	88	—	unknown	22:15–04:35 (good, 6.33 h)	87.1° 22:35	6.48	87%	64.3°
2046-08-13 Mon	80	—	unknown	22:15–03:25 (good, 5.17 h)	87.1° 22:30	6.54	93%	63.1°
2046-08-14 Tue	62	—	unknown	22:10–23:50 (good, 1.67 h)	87.1° 22:25	6.59	97%	63.4°
2046-08-15 Wed	61	—	unknown	22:10–23:10 (good, 1.0 h)	87.1° 22:20	6.65	100%	64.9°
2046-08-16 Thu	63	—	unknown	22:05–23:40 (good, 1.58 h)	87.1° 22:20	6.71	100%	67.6°
2046-08-17 Fri	67	—	unknown	22:05–00:40 (good, 2.58 h)	87.1° 22:15	6.77	98%	71.2°
2046-08-18 Sat	72	—	unknown	22:05–01:20 (good, 3.25 h)	87.1° 22:10	6.82	95%	75.6°
2046-08-19 Sun	77	—	unknown	22:00–01:55 (good, 3.92 h)	87.1° 22:05	6.88	90%	80.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-07-21&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.