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: 09-17 (100), 09-18 (100), 09-30 (100), 10-01 (100), 10-02 (100) — by astronomy; check the weather when the night is within four days.

2034-09-17astronomy score per night — click a bar for that night2034-10-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-09-17 Sun	100	—	unknown	21:05–02:10 (good, 5.08 h)	87.1° 20:10	8.48	24%	68.6°
2034-09-18 Mon	100	—	unknown	21:00–02:10 (good, 5.17 h)	87.1° 20:10	8.53	33%	63.8°
2034-09-19 Tue	95	—	unknown	21:00–02:05 (good, 5.08 h)	87.1° 20:05	8.58	42%	60.1°
2034-09-20 Wed	89	—	unknown	21:00–02:00 (good, 5.0 h)	87.1° 20:00	8.64	51%	57.7°
2034-09-21 Thu	83	—	unknown	20:55–01:55 (good, 5.0 h)	87.1° 19:55	8.69	61%	56.8°
2034-09-22 Fri	65	—	unknown	20:55–01:25 (good, 4.5 h)	87.1° 19:55	8.74	71%	57.6°
2034-09-23 Sat	55	—	unknown	20:50–23:55 (good, 3.08 h)	87.1° 19:50	8.79	79%	60.1°
2034-09-24 Sun	51	—	unknown	20:50–22:50 (good, 2.0 h)	87.1° 19:45	8.84	87%	64.3°
2034-09-25 Mon	50	—	unknown	20:50–22:35 (good, 1.75 h)	87.1° 19:40	8.89	94%	70.0°
2034-09-26 Tue	54	—	unknown	20:45–22:50 (good, 2.08 h)	87.1° 19:35	8.94	98%	76.9°
2034-09-27 Wed	61	—	unknown	20:45–23:25 (good, 2.67 h)	87.1° 19:35	8.99	100%	84.5°
2034-09-28 Thu	70	—	unknown	20:45–00:05 (good, 3.33 h)	87.1° 19:30	9.04	99%	92.5°
2034-09-29 Fri	82	—	unknown	20:40–00:55 (good, 4.25 h)	87.1° 19:25	9.09	95%	100.4°
2034-09-30 Sat	100	—	unknown	20:40–01:00 (good, 4.33 h)	87.1° 19:20	9.13	89%	107.9°
2034-10-01 Sun	100	—	unknown	20:40–01:05 (good, 4.42 h)	87.1° 19:15	9.18	80%	114.4°
2034-10-02 Mon	100	—	unknown	20:35–01:05 (good, 4.5 h)	87.1° 19:15	9.23	70%	119.3°
2034-10-03 Tue	100	—	unknown	20:35–01:05 (good, 4.5 h)	87.1° 19:10	9.28	59%	122.4°
2034-10-04 Wed	100	—	unknown	20:35–01:00 (good, 4.42 h)	87.1° 19:05	9.33	48%	123.2°
2034-10-05 Thu	100	—	unknown	20:30–01:00 (good, 4.5 h)	87.1° 19:00	9.37	37%	121.9°
2034-10-06 Fri	100	—	unknown	20:30–00:55 (good, 4.42 h)	87.1° 19:00	9.42	27%	118.8°
2034-10-07 Sat	100	—	unknown	20:30–00:55 (good, 4.42 h)	87.1° 18:55	9.47	18%	114.2°
2034-10-08 Sun	100	—	unknown	20:25–00:50 (good, 4.42 h)	87.1° 18:50	9.51	11%	108.5°
2034-10-09 Mon	100	—	unknown	20:25–00:45 (good, 4.33 h)	87.1° 18:45	9.56	6%	102.2°
2034-10-10 Tue	100	—	unknown	20:25–00:40 (good, 4.25 h)	87.1° 18:40	9.6	2%	95.6°
2034-10-11 Wed	100	—	unknown	20:20–00:35 (good, 4.25 h)	87.1° 18:40	9.65	0%	88.9°
2034-10-12 Thu	100	—	unknown	20:20–00:35 (good, 4.25 h)	87.1° 18:35	9.69	0%	82.3°
2034-10-13 Fri	100	—	unknown	20:20–00:30 (good, 4.17 h)	87.1° 18:30	9.74	2%	76.0°
2034-10-14 Sat	100	—	unknown	20:15–00:25 (good, 4.17 h)	87.1° 18:25	9.78	6%	70.3°
2034-10-15 Sun	100	—	unknown	20:15–00:20 (good, 4.08 h)	87.1° 18:20	9.82	12%	65.3°
2034-10-16 Mon	97	—	unknown	20:15–00:20 (good, 4.08 h)	87.1° 18:20	9.87	18%	61.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-09-17&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.