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: 09-01 (100), 09-02 (100), 09-03 (100), 09-04 (100), 09-05 (100) — by astronomy; check the weather when the night is within four days.

2046-09-01astronomy score per night — click a bar for that night2046-09-30

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-09-01 Sat	100	—	unknown	21:35–03:15 (good, 5.67 h)	87.1° 21:15	7.62	2%	102.6°
2046-09-02 Sun	100	—	unknown	21:35–03:10 (good, 5.58 h)	87.1° 21:10	7.68	7%	96.1°
2046-09-03 Mon	100	—	unknown	21:30–03:05 (good, 5.58 h)	87.1° 21:05	7.73	15%	89.4°
2046-09-04 Tue	100	—	unknown	21:30–03:05 (good, 5.58 h)	87.1° 21:05	7.79	24%	82.8°
2046-09-05 Wed	100	—	unknown	21:25–03:00 (good, 5.58 h)	87.1° 21:00	7.84	34%	76.8°
2046-09-06 Thu	100	—	unknown	21:25–02:55 (good, 5.5 h)	87.1° 20:55	7.9	45%	71.6°
2046-09-07 Fri	98	—	unknown	21:25–02:50 (good, 5.42 h)	87.1° 20:50	7.95	56%	67.5°
2046-09-08 Sat	90	—	unknown	21:20–02:45 (good, 5.42 h)	87.1° 20:50	8.01	66%	64.7°
2046-09-09 Sun	82	—	unknown	21:20–02:45 (good, 5.42 h)	87.1° 20:45	8.06	75%	63.2°
2046-09-10 Mon	64	—	unknown	21:15–01:40 (good, 4.42 h)	87.1° 20:40	8.11	83%	63.1°
2046-09-11 Tue	56	—	unknown	21:15–23:50 (good, 2.58 h)	87.1° 20:35	8.17	90%	64.3°
2046-09-12 Wed	53	—	unknown	21:15–22:50 (good, 1.58 h)	87.1° 20:30	8.22	95%	66.8°
2046-09-13 Thu	53	—	unknown	21:10–22:40 (good, 1.5 h)	87.1° 20:30	8.27	98%	70.2°
2046-09-14 Fri	55	—	unknown	21:10–23:10 (good, 2.0 h)	87.1° 20:25	8.33	100%	74.4°
2046-09-15 Sat	61	—	unknown	21:05–23:35 (good, 2.5 h)	87.1° 20:20	8.38	100%	79.2°
2046-09-16 Sun	68	—	unknown	21:05–00:05 (good, 3.0 h)	87.1° 20:15	8.43	97%	84.3°
2046-09-17 Mon	77	—	unknown	21:05–00:40 (good, 3.58 h)	87.1° 20:10	8.49	94%	89.7°
2046-09-18 Tue	84	—	unknown	21:00–01:20 (good, 4.33 h)	87.1° 20:10	8.54	88%	95.1°
2046-09-19 Wed	88	—	unknown	21:00–01:40 (good, 4.67 h)	87.1° 20:05	8.59	82%	100.3°
2046-09-20 Thu	100	—	unknown	21:00–01:40 (good, 4.67 h)	87.1° 20:00	8.64	73%	105.3°
2046-09-21 Fri	100	—	unknown	20:55–01:45 (good, 4.83 h)	87.1° 19:55	8.69	64%	109.7°
2046-09-22 Sat	100	—	unknown	20:55–01:45 (good, 4.83 h)	87.1° 19:55	8.74	54%	113.3°
2046-09-23 Sun	100	—	unknown	20:50–01:45 (good, 4.92 h)	87.1° 19:50	8.79	44%	115.9°
2046-09-24 Mon	100	—	unknown	20:50–01:40 (good, 4.83 h)	87.1° 19:45	8.84	33%	117.1°
2046-09-25 Tue	100	—	unknown	20:50–01:40 (good, 4.83 h)	87.1° 19:40	8.89	23%	116.7°
2046-09-26 Wed	100	—	unknown	20:45–01:35 (good, 4.83 h)	87.1° 19:35	8.94	14%	114.5°
2046-09-27 Thu	100	—	unknown	20:45–01:30 (good, 4.75 h)	87.1° 19:35	8.99	7%	110.7°
2046-09-28 Fri	100	—	unknown	20:45–01:30 (good, 4.75 h)	87.1° 19:30	9.04	2%	105.4°
2046-09-29 Sat	100	—	unknown	20:40–01:25 (good, 4.75 h)	87.1° 19:25	9.09	0%	99.1°
2046-09-30 Sun	100	—	unknown	20:40–01:20 (good, 4.67 h)	87.1° 19:20	9.14	1%	92.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-09-01&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.