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.

2031-03-13astronomy score per night — click a bar for that night2031-04-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-03-13 Thu	49	—	unknown	02:10–05:05 (good, 2.92 h)	87.1° 07:30	9.09	75%	73.9°
2031-03-14 Fri	53	—	unknown	02:00–05:05 (good, 3.08 h)	87.1° 07:30	9.04	65%	67.8°
2031-03-15 Sat	60	—	unknown	01:45–05:00 (good, 3.25 h)	87.1° 07:25	8.99	54%	62.8°
2031-03-16 Sun	70	—	unknown	01:25–05:00 (good, 3.58 h)	87.1° 07:20	8.94	42%	59.4°
2031-03-17 Mon	80	—	unknown	01:20–05:00 (good, 3.67 h)	87.1° 07:15	8.89	31%	58.0°
2031-03-18 Tue	88	—	unknown	01:20–04:55 (good, 3.58 h)	87.1° 07:15	8.84	21%	58.8°
2031-03-19 Wed	96	—	unknown	01:15–04:55 (good, 3.67 h)	87.1° 07:10	8.78	13%	61.6°
2031-03-20 Thu	97	—	unknown	01:10–04:55 (good, 3.75 h)	87.1° 07:05	8.73	6%	66.2°
2031-03-21 Fri	98	—	unknown	01:05–04:50 (good, 3.75 h)	87.1° 07:00	8.68	2%	72.0°
2031-03-22 Sat	99	—	unknown	01:05–04:50 (good, 3.75 h)	87.1° 06:55	8.63	0%	78.6°
2031-03-23 Sun	100	—	unknown	01:00–04:45 (good, 3.75 h)	87.1° 06:55	8.58	1%	85.5°
2031-03-24 Mon	100	—	unknown	00:55–04:45 (good, 3.83 h)	87.1° 06:50	8.52	4%	92.5°
2031-03-25 Tue	100	—	unknown	00:50–04:45 (good, 3.92 h)	87.1° 06:45	8.47	8%	99.2°
2031-03-26 Wed	100	—	unknown	00:45–04:40 (good, 3.92 h)	87.1° 06:40	8.42	15%	105.4°
2031-03-27 Thu	100	—	unknown	00:45–04:40 (good, 3.92 h)	87.1° 06:35	8.36	22%	111.0°
2031-03-28 Fri	100	—	unknown	00:40–04:40 (good, 4.0 h)	87.1° 06:35	8.31	31%	115.6°
2031-03-29 Sat	100	—	unknown	00:40–05:35 (good, 3.92 h)	87.1° 07:30	8.26	40%	119.1°
2031-03-30 Sun	100	—	unknown	01:35–05:35 (good, 4.0 h)	87.1° 07:25	8.2	49%	121.4°
2031-03-31 Mon	100	—	unknown	01:35–05:30 (good, 3.92 h)	87.1° 07:20	8.15	59%	122.1°
2031-04-01 Tue	100	—	unknown	01:30–05:30 (good, 4.0 h)	87.1° 07:20	8.09	68%	121.4°
2031-04-02 Wed	100	—	unknown	01:30–05:30 (good, 4.0 h)	87.1° 07:15	8.04	76%	119.1°
2031-04-03 Thu	99	—	unknown	01:30–05:25 (good, 3.92 h)	87.1° 07:10	7.98	84%	115.3°
2031-04-04 Fri	96	—	unknown	01:30–05:25 (good, 3.92 h)	87.1° 07:05	7.93	91%	110.4°
2031-04-05 Sat	78	—	unknown	01:35–05:20 (good, 3.75 h)	87.1° 07:00	7.87	96%	104.3°
2031-04-06 Sun	70	—	unknown	01:40–05:20 (good, 3.67 h)	87.1° 07:00	7.82	99%	97.6°
2031-04-07 Mon	63	—	unknown	02:15–05:20 (good, 3.08 h)	87.1° 06:55	7.76	100%	90.3°
2031-04-08 Tue	56	—	unknown	02:35–05:15 (good, 2.67 h)	87.1° 06:50	7.7	98%	82.9°
2031-04-09 Wed	54	—	unknown	02:45–05:15 (good, 2.5 h)	87.1° 06:45	7.65	94%	75.7°
2031-04-10 Thu	53	—	unknown	02:20–05:10 (good, 2.83 h)	87.1° 06:40	7.59	87%	69.1°
2031-04-11 Fri	58	—	unknown	01:15–05:10 (good, 3.92 h)	87.1° 06:40	7.53	78%	63.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-03-13&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.