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: 03-19 (82), 03-04 (81), 03-05 (81), 03-07 (80), 03-02 (79) — by astronomy; check the weather when the night is within four days.

2047-02-18astronomy score per night — click a bar for that night2047-03-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-02-18 Mon	53	—	unknown	03:10–05:40 (good, 2.5 h)	87.1° 09:05	10.13	32%	67.2°
2047-02-19 Tue	58	—	unknown	03:05–05:40 (good, 2.58 h)	87.1° 09:00	10.09	22%	64.1°
2047-02-20 Wed	64	—	unknown	03:00–05:40 (good, 2.67 h)	87.1° 08:55	10.04	14%	62.4°
2047-02-21 Thu	67	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:50	10.0	8%	62.3°
2047-02-22 Fri	69	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 08:45	9.96	3%	63.7°
2047-02-23 Sat	71	—	unknown	02:50–05:35 (good, 2.75 h)	87.1° 08:45	9.92	1%	66.4°
2047-02-24 Sun	71	—	unknown	02:45–05:35 (good, 2.83 h)	87.1° 08:40	9.87	0%	70.1°
2047-02-25 Mon	72	—	unknown	02:40–05:30 (good, 2.83 h)	87.1° 08:35	9.83	1%	74.6°
2047-02-26 Tue	74	—	unknown	02:35–05:30 (good, 2.92 h)	87.1° 08:30	9.79	4%	79.7°
2047-02-27 Wed	75	—	unknown	02:35–05:30 (good, 2.92 h)	87.1° 08:30	9.74	9%	85.1°
2047-02-28 Thu	75	—	unknown	02:30–05:25 (good, 2.92 h)	87.1° 08:25	9.7	15%	90.6°
2047-03-01 Fri	77	—	unknown	02:25–05:25 (good, 3.0 h)	87.1° 08:20	9.65	23%	96.1°
2047-03-02 Sat	79	—	unknown	02:20–05:25 (good, 3.08 h)	87.1° 08:15	9.61	31%	101.4°
2047-03-03 Sun	79	—	unknown	02:15–05:20 (good, 3.08 h)	87.1° 08:10	9.56	40%	106.3°
2047-03-04 Mon	81	—	unknown	02:15–05:20 (good, 3.08 h)	87.1° 08:10	9.51	50%	110.7°
2047-03-05 Tue	81	—	unknown	02:15–05:20 (good, 3.08 h)	87.1° 08:05	9.47	60%	114.3°
2047-03-06 Wed	79	—	unknown	02:15–05:15 (good, 3.0 h)	87.1° 08:00	9.42	70%	116.8°
2047-03-07 Thu	80	—	unknown	02:10–05:15 (good, 3.08 h)	87.1° 07:55	9.37	79%	117.9°
2047-03-08 Fri	79	—	unknown	02:10–05:15 (good, 3.08 h)	87.1° 07:50	9.32	87%	117.4°
2047-03-09 Sat	69	—	unknown	02:10–05:10 (good, 3.0 h)	87.1° 07:50	9.28	94%	115.1°
2047-03-10 Sun	65	—	unknown	02:10–05:10 (good, 3.0 h)	87.1° 07:45	9.23	98%	111.1°
2047-03-11 Mon	60	—	unknown	02:10–05:10 (good, 3.0 h)	87.1° 07:40	9.18	100%	105.7°
2047-03-12 Tue	55	—	unknown	02:10–05:05 (good, 2.92 h)	87.1° 07:35	9.13	99%	99.3°
2047-03-13 Wed	53	—	unknown	02:20–05:05 (good, 2.75 h)	87.1° 07:30	9.08	95%	92.4°
2047-03-14 Thu	51	—	unknown	02:20–05:05 (good, 2.75 h)	87.1° 07:30	9.03	88%	85.4°
2047-03-15 Fri	52	—	unknown	02:00–05:00 (good, 3.0 h)	87.1° 07:25	8.98	79%	78.7°
2047-03-16 Sat	56	—	unknown	01:50–05:00 (good, 3.17 h)	87.1° 07:20	8.93	69%	72.8°
2047-03-17 Sun	63	—	unknown	01:20–05:00 (good, 3.67 h)	87.1° 07:15	8.88	58%	68.0°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-02-18&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.