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.

2039-02-27astronomy score per night — click a bar for that night2039-03-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-02-27 Sun	75	—	unknown	02:35–05:30 (good, 2.92 h)	87.1° 08:30	9.74	22%	102.8°
2039-02-28 Mon	75	—	unknown	02:30–05:25 (good, 2.92 h)	87.1° 08:25	9.7	30%	107.4°
2039-03-01 Tue	77	—	unknown	02:25–05:25 (good, 3.0 h)	87.1° 08:20	9.65	39%	111.3°
2039-03-02 Wed	79	—	unknown	02:20–05:25 (good, 3.08 h)	87.1° 08:15	9.61	48%	114.4°
2039-03-03 Thu	79	—	unknown	02:25–05:20 (good, 2.92 h)	87.1° 08:10	9.56	58%	116.4°
2039-03-04 Fri	79	—	unknown	02:20–05:20 (good, 3.0 h)	87.1° 08:10	9.52	67%	117.2°
2039-03-05 Sat	78	—	unknown	02:20–05:20 (good, 3.0 h)	87.1° 08:05	9.47	76%	116.6°
2039-03-06 Sun	75	—	unknown	02:20–05:15 (good, 2.92 h)	87.1° 08:00	9.42	84%	114.8°
2039-03-07 Mon	65	—	unknown	02:20–05:15 (good, 2.92 h)	87.1° 07:55	9.38	91%	111.6°
2039-03-08 Tue	61	—	unknown	02:20–05:15 (good, 2.92 h)	87.1° 07:50	9.33	96%	107.2°
2039-03-09 Wed	54	—	unknown	02:25–05:10 (good, 2.75 h)	87.1° 07:50	9.28	99%	101.8°
2039-03-10 Thu	49	—	unknown	02:55–05:10 (good, 2.25 h)	87.1° 07:45	9.23	100%	95.7°
2039-03-11 Fri	45	—	unknown	03:20–05:10 (good, 1.83 h)	87.1° 07:40	9.18	98%	89.2°
2039-03-12 Sat	42	—	unknown	03:30–05:05 (good, 1.58 h)	87.1° 07:35	9.13	93%	82.7°
2039-03-13 Sun	43	—	unknown	03:25–05:05 (good, 1.67 h)	87.1° 07:30	9.08	86%	76.5°
2039-03-14 Mon	46	—	unknown	02:40–05:05 (good, 2.42 h)	87.1° 07:30	9.03	77%	71.1°
2039-03-15 Tue	51	—	unknown	01:55–05:00 (good, 3.08 h)	87.1° 07:25	8.98	67%	66.9°
2039-03-16 Wed	61	—	unknown	01:45–05:00 (good, 3.25 h)	87.1° 07:20	8.93	56%	64.1°
2039-03-17 Thu	73	—	unknown	01:20–05:00 (good, 3.67 h)	87.1° 07:15	8.88	44%	63.0°
2039-03-18 Fri	84	—	unknown	01:20–04:55 (good, 3.58 h)	87.1° 07:15	8.83	33%	63.5°
2039-03-19 Sat	93	—	unknown	01:15–04:55 (good, 3.67 h)	87.1° 07:10	8.78	24%	65.7°
2039-03-20 Sun	97	—	unknown	01:10–04:55 (good, 3.75 h)	87.1° 07:05	8.73	15%	69.2°
2039-03-21 Mon	98	—	unknown	01:05–04:50 (good, 3.75 h)	87.1° 07:00	8.68	8%	73.7°
2039-03-22 Tue	99	—	unknown	01:05–04:50 (good, 3.75 h)	87.1° 06:55	8.63	4%	78.8°
2039-03-23 Wed	100	—	unknown	01:00–04:45 (good, 3.75 h)	87.1° 06:55	8.57	1%	84.4°
2039-03-24 Thu	100	—	unknown	00:55–04:45 (good, 3.83 h)	87.1° 06:50	8.52	0%	90.1°
2039-03-25 Fri	100	—	unknown	00:50–04:45 (good, 3.92 h)	87.1° 06:45	8.47	2%	95.7°
2039-03-26 Sat	100	—	unknown	00:45–05:40 (good, 3.92 h)	87.1° 07:40	8.42	5%	100.9°
2039-03-27 Sun	100	—	unknown	01:45–05:40 (good, 3.92 h)	87.1° 07:35	8.36	10%	105.7°
2039-03-28 Mon	100	—	unknown	01:40–05:35 (good, 3.92 h)	87.1° 07:35	8.31	16%	109.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-02-27&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.