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: 05-19 (100), 05-20 (100), 05-21 (100), 05-22 (100), 05-23 (100) — by astronomy; check the weather when the night is within four days.

2036-05-19astronomy score per night — click a bar for that night2036-06-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-05-19 Mon	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:05	5.34	35%	79.0°
2036-05-20 Tue	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:00	5.29	26%	85.3°
2036-05-21 Wed	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 04:00	5.24	18%	91.9°
2036-05-22 Thu	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:55	5.19	10%	98.6°
2036-05-23 Fri	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:50	5.15	5%	105.2°
2036-05-24 Sat	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:45	5.1	1%	111.3°
2036-05-25 Sun	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:40	5.06	0%	116.3°
2036-05-26 Mon	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:40	5.01	2%	119.9°
2036-05-27 Tue	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:35	4.97	6%	121.3°
2036-05-28 Wed	100	—	unknown	22:55–03:50 (good, 4.92 h)	87.1° 03:30	4.93	13%	120.6°
2036-05-29 Thu	100	—	unknown	22:55–03:50 (good, 4.92 h)	87.1° 03:25	4.89	22%	117.7°
2036-05-30 Fri	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:25	4.85	33%	113.0°
2036-05-31 Sat	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:20	4.81	44%	107.1°
2036-06-01 Sun	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:15	4.78	55%	100.5°
2036-06-02 Mon	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:10	4.74	66%	93.5°
2036-06-03 Tue	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:05	4.71	76%	86.5°
2036-06-04 Wed	80	—	unknown	23:00–03:40 (good, 4.67 h)	87.1° 03:05	4.68	84%	79.8°
2036-06-05 Thu	72	—	unknown	23:30–03:40 (good, 4.17 h)	87.1° 03:00	4.65	91%	73.5°
2036-06-06 Fri	61	—	unknown	00:10–03:40 (good, 3.5 h)	87.1° 02:55	4.62	96%	68.1°
2036-06-07 Sat	53	—	unknown	02:20–03:40 (good, 1.33 h)	87.1° 02:50	4.59	99%	63.7°
2036-06-08 Sun	49	—	unknown	03:35–03:40 (good, 0.08 h)	87.1° 02:45	4.57	100%	60.6°
2036-06-09 Mon	49	—	unknown	23:05–03:40 (marginal, 4.58 h)	87.1° 02:45	4.54	99%	58.9°
2036-06-10 Tue	55	—	unknown	23:05–01:25 (good, 2.33 h)	87.1° 02:40	4.52	96%	58.8°
2036-06-11 Wed	64	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:35	4.5	91%	60.2°
2036-06-12 Thu	98	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:30	4.49	85%	63.0°
2036-06-13 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:30	4.47	78%	66.9°
2036-06-14 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:25	4.46	70%	71.7°
2036-06-15 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:20	4.45	61%	77.3°
2036-06-16 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:15	4.44	51%	83.3°
2036-06-17 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:10	4.43	41%	89.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-05-19&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.