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: 10-07 (100), 10-08 (100), 10-09 (100), 10-10 (100), 10-11 (100) — by astronomy; check the weather when the night is within four days.

2028-09-26astronomy score per night — click a bar for that night2028-10-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-09-26 Tue	80	—	unknown	20:45–01:35 (good, 4.83 h)	87.1° 19:35	8.96	64%	61.8°
2028-09-27 Wed	62	—	unknown	20:45–01:00 (good, 4.25 h)	87.1° 19:30	9.01	73%	62.0°
2028-09-28 Thu	54	—	unknown	20:40–23:25 (good, 2.75 h)	87.1° 19:25	9.06	81%	63.5°
2028-09-29 Fri	49	—	unknown	20:40–22:30 (good, 1.83 h)	87.1° 19:25	9.11	88%	66.3°
2028-09-30 Sat	47	—	unknown	20:40–22:10 (good, 1.5 h)	87.1° 19:20	9.16	93%	70.0°
2028-10-01 Sun	48	—	unknown	20:35–22:10 (good, 1.58 h)	87.1° 19:15	9.2	97%	74.4°
2028-10-02 Mon	51	—	unknown	20:35–22:25 (good, 1.83 h)	87.1° 19:10	9.25	99%	79.5°
2028-10-03 Tue	56	—	unknown	20:35–22:50 (good, 2.25 h)	87.1° 19:05	9.3	100%	84.9°
2028-10-04 Wed	64	—	unknown	20:30–23:25 (good, 2.92 h)	87.1° 19:05	9.35	98%	90.6°
2028-10-05 Thu	72	—	unknown	20:30–00:05 (good, 3.58 h)	87.1° 19:00	9.39	95%	96.3°
2028-10-06 Fri	80	—	unknown	20:30–00:30 (good, 4.0 h)	87.1° 18:55	9.44	90%	101.8°
2028-10-07 Sat	100	—	unknown	20:25–00:30 (good, 4.08 h)	87.1° 18:50	9.49	84%	107.0°
2028-10-08 Sun	100	—	unknown	20:25–00:35 (good, 4.17 h)	87.1° 18:50	9.53	76%	111.5°
2028-10-09 Mon	100	—	unknown	20:25–00:35 (good, 4.17 h)	87.1° 18:45	9.58	66%	115.1°
2028-10-10 Tue	100	—	unknown	20:20–00:35 (good, 4.25 h)	87.1° 18:40	9.62	56%	117.5°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-09-26&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.