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: 08-23 (100), 08-24 (100), 08-25 (100), 08-26 (100), 08-27 (100) — by astronomy; check the weather when the night is within four days.

2028-08-23astronomy score per night — click a bar for that night2028-09-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-08-23 Wed	100	—	unknown	21:50–03:50 (good, 6.0 h)	87.1° 21:50	7.13	17%	92.1°
2028-08-24 Thu	100	—	unknown	21:50–03:45 (good, 5.92 h)	87.1° 21:45	7.19	27%	85.4°
2028-08-25 Fri	100	—	unknown	21:50–03:40 (good, 5.83 h)	87.1° 21:40	7.25	38%	79.0°
2028-08-26 Sat	100	—	unknown	21:45–03:35 (good, 5.83 h)	87.1° 21:35	7.3	49%	73.4°
2028-08-27 Sun	100	—	unknown	21:45–03:30 (good, 5.75 h)	87.1° 21:35	7.36	59%	68.7°
2028-08-28 Mon	93	—	unknown	21:40–03:30 (good, 5.83 h)	87.1° 21:30	7.42	69%	65.1°
2028-08-29 Tue	86	—	unknown	21:40–03:25 (good, 5.75 h)	87.1° 21:25	7.47	78%	62.8°
2028-08-30 Wed	68	—	unknown	21:40–02:40 (good, 5.0 h)	87.1° 21:20	7.53	86%	62.0°
2028-08-31 Thu	59	—	unknown	21:35–00:25 (good, 2.83 h)	87.1° 21:15	7.58	92%	62.5°
2028-09-01 Fri	54	—	unknown	21:35–22:20 (good, 0.75 h)	87.1° 21:15	7.64	96%	64.3°
2028-09-02 Sat	54	—	unknown	21:30–22:25 (good, 0.92 h)	87.1° 21:10	7.7	99%	67.2°
2028-09-03 Sun	56	—	unknown	21:30–23:05 (good, 1.58 h)	87.1° 21:05	7.75	100%	71.1°
2028-09-04 Mon	61	—	unknown	21:30–23:55 (good, 2.42 h)	87.1° 21:00	7.81	99%	75.7°
2028-09-05 Tue	70	—	unknown	21:25–00:30 (good, 3.08 h)	87.1° 21:00	7.86	96%	80.8°
2028-09-06 Wed	78	—	unknown	21:25–01:10 (good, 3.75 h)	87.1° 20:55	7.92	92%	86.3°
2028-09-07 Thu	83	—	unknown	21:20–01:50 (good, 4.5 h)	87.1° 20:50	7.97	86%	91.9°
2028-09-08 Fri	100	—	unknown	21:20–02:20 (good, 5.0 h)	87.1° 20:45	8.03	79%	97.5°
2028-09-09 Sat	100	—	unknown	21:20–02:20 (good, 5.0 h)	87.1° 20:40	8.08	71%	102.9°
2028-09-10 Sun	100	—	unknown	21:15–02:25 (good, 5.17 h)	87.1° 20:40	8.13	61%	107.9°
2028-09-11 Mon	100	—	unknown	21:15–02:25 (good, 5.17 h)	87.1° 20:35	8.19	51%	112.3°
2028-09-12 Tue	100	—	unknown	21:15–02:25 (good, 5.17 h)	87.1° 20:30	8.24	41%	115.7°
2028-09-13 Wed	100	—	unknown	21:10–02:20 (good, 5.17 h)	87.1° 20:25	8.29	30%	117.7°
2028-09-14 Thu	100	—	unknown	21:10–02:20 (good, 5.17 h)	87.1° 20:20	8.35	20%	118.1°
2028-09-15 Fri	100	—	unknown	21:05–02:15 (good, 5.17 h)	87.1° 20:20	8.4	12%	116.5°
2028-09-16 Sat	100	—	unknown	21:05–02:15 (good, 5.17 h)	87.1° 20:15	8.45	5%	113.1°
2028-09-17 Sun	100	—	unknown	21:05–02:10 (good, 5.08 h)	87.1° 20:10	8.5	1%	108.1°
2028-09-18 Mon	100	—	unknown	21:00–02:05 (good, 5.08 h)	87.1° 20:05	8.56	0%	101.9°
2028-09-19 Tue	100	—	unknown	21:00–02:00 (good, 5.0 h)	87.1° 20:00	8.61	2%	95.0°
2028-09-20 Wed	100	—	unknown	20:55–02:00 (good, 5.08 h)	87.1° 20:00	8.66	7%	87.9°
2028-09-21 Thu	100	—	unknown	20:55–01:55 (good, 5.0 h)	87.1° 19:55	8.71	14%	81.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-08-23&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.