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: 03-29 (100), 03-30 (100), 03-31 (100), 04-01 (100), 04-02 (100) — by astronomy; check the weather when the night is within four days.

2030-03-17astronomy score per night — click a bar for that night2030-04-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-03-17 Sun	74	—	unknown	01:40–05:00 (good, 3.33 h)	87.1° 07:15	8.87	96%	112.9°
2030-03-18 Mon	67	—	unknown	01:40–04:55 (good, 3.25 h)	87.1° 07:10	8.82	99%	107.3°
2030-03-19 Tue	61	—	unknown	01:45–04:55 (good, 3.17 h)	87.1° 07:10	8.77	100%	100.6°
2030-03-20 Wed	56	—	unknown	02:00–04:50 (good, 2.83 h)	87.1° 07:05	8.72	98%	93.3°
2030-03-21 Thu	52	—	unknown	02:10–04:50 (good, 2.67 h)	87.1° 07:00	8.67	93%	85.8°
2030-03-22 Fri	52	—	unknown	02:00–04:50 (good, 2.83 h)	87.1° 06:55	8.62	86%	78.5°
2030-03-23 Sat	53	—	unknown	01:25–04:45 (good, 3.33 h)	87.1° 06:50	8.56	77%	71.8°
2030-03-24 Sun	59	—	unknown	01:15–04:45 (good, 3.5 h)	87.1° 06:50	8.51	66%	66.2°
2030-03-25 Mon	71	—	unknown	00:50–04:45 (good, 3.92 h)	87.1° 06:45	8.46	55%	62.1°
2030-03-26 Tue	82	—	unknown	00:45–04:40 (good, 3.92 h)	87.1° 06:40	8.41	44%	59.7°
2030-03-27 Wed	92	—	unknown	00:40–04:40 (good, 4.0 h)	87.1° 06:35	8.35	34%	59.3°
2030-03-28 Thu	98	—	unknown	00:40–04:35 (good, 3.92 h)	87.1° 06:30	8.3	24%	60.7°
2030-03-29 Fri	100	—	unknown	00:35–04:35 (good, 4.0 h)	87.1° 06:30	8.24	16%	63.7°
2030-03-30 Sat	100	—	unknown	00:30–05:35 (good, 4.08 h)	87.1° 07:25	8.19	9%	68.0°
2030-03-31 Sun	100	—	unknown	01:25–05:30 (good, 4.08 h)	87.1° 07:20	8.14	4%	73.2°
2030-04-01 Mon	100	—	unknown	01:20–05:30 (good, 4.17 h)	87.1° 07:15	8.08	1%	78.9°
2030-04-02 Tue	100	—	unknown	01:20–05:25 (good, 4.08 h)	87.1° 07:15	8.03	0%	85.0°
2030-04-03 Wed	100	—	unknown	01:15–05:25 (good, 4.17 h)	87.1° 07:10	7.97	1%	91.3°
2030-04-04 Thu	100	—	unknown	01:10–05:25 (good, 4.25 h)	87.1° 07:05	7.91	4%	97.4°
2030-04-05 Fri	100	—	unknown	01:05–05:20 (good, 4.25 h)	87.1° 07:00	7.86	8%	103.2°
2030-04-06 Sat	100	—	unknown	01:05–05:20 (good, 4.25 h)	87.1° 06:55	7.8	14%	108.5°
2030-04-07 Sun	100	—	unknown	01:00–05:20 (good, 4.33 h)	87.1° 06:55	7.75	21%	113.2°
2030-04-08 Mon	100	—	unknown	01:00–05:15 (good, 4.25 h)	87.1° 06:50	7.69	29%	116.9°
2030-04-09 Tue	100	—	unknown	00:55–05:15 (good, 4.33 h)	87.1° 06:45	7.63	38%	119.6°
2030-04-10 Wed	100	—	unknown	00:50–05:10 (good, 4.33 h)	87.1° 06:40	7.58	48%	120.8°
2030-04-11 Thu	100	—	unknown	00:50–05:10 (good, 4.33 h)	87.1° 06:35	7.52	58%	120.5°
2030-04-12 Fri	100	—	unknown	00:50–05:10 (good, 4.33 h)	87.1° 06:35	7.46	68%	118.6°
2030-04-13 Sat	100	—	unknown	00:50–05:05 (good, 4.25 h)	87.1° 06:30	7.41	77%	115.1°
2030-04-14 Sun	100	—	unknown	00:50–05:05 (good, 4.25 h)	87.1° 06:25	7.35	86%	110.0°
2030-04-15 Mon	87	—	unknown	00:50–05:00 (good, 4.17 h)	87.1° 06:20	7.29	93%	103.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-03-17&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.