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: 03-23 (100), 03-24 (100), 03-25 (100), 03-26 (100), 03-27 (100) — by astronomy; check the weather when the night is within four days.

2047-03-18astronomy score per night — click a bar for that night2047-04-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-03-18 Mon	73	—	unknown	01:20–04:55 (good, 3.58 h)	87.1° 07:15	8.83	47%	64.5°
2047-03-19 Tue	82	—	unknown	01:15–04:55 (good, 3.67 h)	87.1° 07:10	8.78	37%	62.5°
2047-03-20 Wed	89	—	unknown	01:10–04:50 (good, 3.67 h)	87.1° 07:05	8.73	27%	62.0°
2047-03-21 Thu	96	—	unknown	01:05–04:50 (good, 3.75 h)	87.1° 07:00	8.67	18%	63.1°
2047-03-22 Fri	99	—	unknown	01:05–04:50 (good, 3.75 h)	87.1° 06:55	8.62	12%	65.5°
2047-03-23 Sat	100	—	unknown	01:00–04:45 (good, 3.75 h)	87.1° 06:55	8.57	6%	69.0°
2047-03-24 Sun	100	—	unknown	00:55–04:45 (good, 3.83 h)	87.1° 06:50	8.52	2%	73.4°
2047-03-25 Mon	100	—	unknown	00:50–04:45 (good, 3.92 h)	87.1° 06:45	8.46	0%	78.3°
2047-03-26 Tue	100	—	unknown	00:45–04:40 (good, 3.92 h)	87.1° 06:40	8.41	0%	83.6°
2047-03-27 Wed	100	—	unknown	00:45–04:40 (good, 3.92 h)	87.1° 06:35	8.36	2%	89.2°
2047-03-28 Thu	100	—	unknown	00:40–04:35 (good, 3.92 h)	87.1° 06:35	8.3	6%	94.7°
2047-03-29 Fri	100	—	unknown	00:35–04:35 (good, 4.0 h)	87.1° 06:30	8.25	10%	100.1°
2047-03-30 Sat	100	—	unknown	00:30–05:35 (good, 4.08 h)	87.1° 07:25	8.2	17%	105.2°
2047-03-31 Sun	100	—	unknown	01:25–05:30 (good, 4.08 h)	87.1° 07:20	8.14	25%	109.7°
2047-04-01 Mon	100	—	unknown	01:25–05:30 (good, 4.08 h)	87.1° 07:20	8.09	33%	113.5°
2047-04-02 Tue	100	—	unknown	01:25–05:30 (good, 4.08 h)	87.1° 07:15	8.03	43%	116.3°
2047-04-03 Wed	100	—	unknown	01:20–05:25 (good, 4.08 h)	87.1° 07:10	7.98	53%	117.9°
2047-04-04 Thu	100	—	unknown	01:20–05:25 (good, 4.08 h)	87.1° 07:05	7.92	63%	118.0°
2047-04-05 Fri	100	—	unknown	01:20–05:20 (good, 4.0 h)	87.1° 07:00	7.87	74%	116.4°
2047-04-06 Sat	100	—	unknown	01:20–05:20 (good, 4.0 h)	87.1° 07:00	7.81	83%	113.2°
2047-04-07 Sun	86	—	unknown	01:20–05:20 (good, 4.0 h)	87.1° 06:55	7.75	91%	108.4°
2047-04-08 Mon	78	—	unknown	01:25–05:15 (good, 3.83 h)	87.1° 06:50	7.7	96%	102.4°
2047-04-09 Tue	70	—	unknown	01:35–05:15 (good, 3.67 h)	87.1° 06:45	7.64	99%	95.6°
2047-04-10 Wed	63	—	unknown	02:00–05:10 (good, 3.17 h)	87.1° 06:40	7.58	99%	88.4°
2047-04-11 Thu	59	—	unknown	02:10–05:10 (good, 3.0 h)	87.1° 06:40	7.53	96%	81.3°
2047-04-12 Fri	58	—	unknown	01:50–05:10 (good, 3.33 h)	87.1° 06:35	7.47	91%	74.8°
2047-04-13 Sat	61	—	unknown	01:05–05:05 (good, 4.0 h)	87.1° 06:30	7.41	83%	69.3°
2047-04-14 Sun	78	—	unknown	00:30–05:05 (good, 4.58 h)	87.1° 06:25	7.36	73%	65.2°
2047-04-15 Mon	88	—	unknown	00:30–05:00 (good, 4.5 h)	87.1° 06:25	7.3	63%	62.6°
2047-04-16 Tue	94	—	unknown	00:25–05:00 (good, 4.58 h)	87.1° 06:20	7.24	52%	61.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-03-18&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.