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: 10-11 (100), 10-12 (100), 10-13 (100), 10-14 (100), 10-15 (100) — by astronomy; check the weather when the night is within four days.

2028-10-11astronomy score per night — click a bar for that night2028-11-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-10-11 Wed	100	—	unknown	20:20–00:30 (good, 4.17 h)	87.1° 18:35	9.67	45%	118.4°
2028-10-12 Thu	100	—	unknown	20:20–00:30 (good, 4.17 h)	87.1° 18:30	9.71	34%	117.5°
2028-10-13 Fri	100	—	unknown	20:15–00:25 (good, 4.17 h)	87.1° 18:30	9.76	24%	114.9°
2028-10-14 Sat	100	—	unknown	20:15–00:25 (good, 4.17 h)	87.1° 18:25	9.8	15%	110.5°
2028-10-15 Sun	100	—	unknown	20:15–00:20 (good, 4.08 h)	87.1° 18:20	9.84	7%	104.9°
2028-10-16 Mon	100	—	unknown	20:15–00:15 (good, 4.0 h)	87.1° 18:15	9.89	2%	98.2°
2028-10-17 Tue	100	—	unknown	20:10–00:10 (good, 4.0 h)	87.1° 18:10	9.93	0%	91.2°
2028-10-18 Wed	100	—	unknown	20:10–00:10 (good, 4.0 h)	87.1° 18:10	9.97	1%	84.1°
2028-10-19 Thu	100	—	unknown	20:10–00:05 (good, 3.92 h)	87.1° 18:05	10.01	5%	77.4°
2028-10-20 Fri	100	—	unknown	20:05–00:00 (good, 3.92 h)	87.1° 18:00	10.06	11%	71.6°
2028-10-21 Sat	99	—	unknown	20:05–23:55 (good, 3.83 h)	87.1° 17:55	10.1	19%	66.9°
2028-10-22 Sun	87	—	unknown	20:05–23:50 (good, 3.75 h)	87.1° 17:55	10.14	28%	63.6°
2028-10-23 Mon	76	—	unknown	20:05–23:50 (good, 3.75 h)	87.1° 17:50	10.18	37%	61.8°
2028-10-24 Tue	66	—	unknown	20:00–23:30 (good, 3.5 h)	87.1° 17:45	10.22	47%	61.6°
2028-10-25 Wed	56	—	unknown	20:00–23:15 (good, 3.25 h)	87.1° 17:40	10.26	57%	62.7°
2028-10-26 Thu	49	—	unknown	20:00–22:50 (good, 2.83 h)	87.1° 17:35	10.3	66%	65.2°
2028-10-27 Fri	44	—	unknown	20:00–21:45 (good, 1.75 h)	87.1° 17:35	10.33	75%	68.7°
2028-10-28 Sat	41	—	unknown	19:55–21:15 (good, 1.33 h)	87.1° 17:30	10.37	82%	73.0°
2028-10-29 Sun	40	—	unknown	18:55–20:05 (good, 1.17 h)	87.1° 16:25	10.41	89%	77.9°
2028-10-30 Mon	41	—	unknown	18:55–20:10 (good, 1.25 h)	87.1° 16:20	10.45	94%	83.3°
2028-10-31 Tue	44	—	unknown	18:55–20:30 (good, 1.58 h)	87.1° 16:15	10.48	98%	89.0°
2028-11-01 Wed	49	—	unknown	18:50–21:00 (good, 2.17 h)	87.1° 16:15	10.52	100%	94.8°
2028-11-02 Thu	53	—	unknown	18:50–21:30 (good, 2.67 h)	87.1° 16:10	10.56	100%	100.5°
2028-11-03 Fri	59	—	unknown	18:50–21:40 (good, 2.83 h)	87.1° 16:05	10.59	98%	105.9°
2028-11-04 Sat	64	—	unknown	18:50–21:45 (good, 2.92 h)	87.1° 16:00	10.63	94%	110.7°
2028-11-05 Sun	75	—	unknown	18:50–21:45 (good, 2.92 h)	87.1° 16:00	10.66	88%	114.6°
2028-11-06 Mon	78	—	unknown	18:45–21:45 (good, 3.0 h)	87.1° 15:55	10.69	80%	117.3°
2028-11-07 Tue	78	—	unknown	18:45–21:45 (good, 3.0 h)	87.1° 15:50	10.73	71%	118.6°
2028-11-08 Wed	77	—	unknown	18:45–21:45 (good, 3.0 h)	87.1° 15:45	10.76	61%	118.2°
2028-11-09 Thu	76	—	unknown	18:45–21:40 (good, 2.92 h)	87.1° 15:40	10.79	50%	116.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-10-11&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.