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.

2028-03-19astronomy score per night — click a bar for that night2028-04-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-03-19 Sun	88	—	unknown	01:10–04:55 (good, 3.75 h)	87.1° 07:05	8.75	31%	62.7°
2028-03-20 Mon	94	—	unknown	01:10–04:50 (good, 3.67 h)	87.1° 07:00	8.7	23%	63.0°
2028-03-21 Tue	99	—	unknown	01:05–04:50 (good, 3.75 h)	87.1° 07:00	8.64	16%	64.6°
2028-03-22 Wed	99	—	unknown	01:00–04:50 (good, 3.83 h)	87.1° 06:55	8.59	9%	67.2°
2028-03-23 Thu	100	—	unknown	00:55–04:45 (good, 3.83 h)	87.1° 06:50	8.54	5%	70.8°
2028-03-24 Fri	100	—	unknown	00:50–04:45 (good, 3.92 h)	87.1° 06:45	8.49	2%	75.2°
2028-03-25 Sat	100	—	unknown	00:50–05:40 (good, 3.83 h)	87.1° 07:40	8.43	0%	80.2°
2028-03-26 Sun	100	—	unknown	01:45–05:40 (good, 3.92 h)	87.1° 07:40	8.38	1%	85.6°
2028-03-27 Mon	100	—	unknown	01:40–05:40 (good, 4.0 h)	87.1° 07:35	8.33	3%	91.2°
2028-03-28 Tue	100	—	unknown	01:35–05:35 (good, 4.0 h)	87.1° 07:30	8.27	7%	96.9°
2028-03-29 Wed	100	—	unknown	01:30–05:35 (good, 4.08 h)	87.1° 07:25	8.22	13%	102.4°
2028-03-30 Thu	100	—	unknown	01:30–05:30 (good, 4.0 h)	87.1° 07:25	8.16	21%	107.4°
2028-03-31 Fri	100	—	unknown	01:30–05:30 (good, 4.0 h)	87.1° 07:20	8.11	30%	111.8°
2028-04-01 Sat	100	—	unknown	01:25–05:30 (good, 4.08 h)	87.1° 07:15	8.05	40%	115.1°
2028-04-02 Sun	100	—	unknown	01:25–05:25 (good, 4.0 h)	87.1° 07:10	8.0	51%	117.1°
2028-04-03 Mon	100	—	unknown	01:20–05:25 (good, 4.08 h)	87.1° 07:05	7.94	63%	117.4°
2028-04-04 Tue	100	—	unknown	01:20–05:25 (good, 4.08 h)	87.1° 07:05	7.89	73%	115.9°
2028-04-05 Wed	100	—	unknown	01:20–05:20 (good, 4.0 h)	87.1° 07:00	7.83	83%	112.7°
2028-04-06 Thu	86	—	unknown	01:20–05:20 (good, 4.0 h)	87.1° 06:55	7.78	91%	107.9°
2028-04-07 Fri	77	—	unknown	01:25–05:15 (good, 3.83 h)	87.1° 06:50	7.72	97%	102.1°
2028-04-08 Sat	70	—	unknown	01:40–05:15 (good, 3.58 h)	87.1° 06:45	7.66	100%	95.5°
2028-04-09 Sun	64	—	unknown	02:00–05:15 (good, 3.25 h)	87.1° 06:45	7.61	100%	88.7°
2028-04-10 Mon	59	—	unknown	02:05–05:10 (good, 3.08 h)	87.1° 06:40	7.55	97%	82.2°
2028-04-11 Tue	59	—	unknown	01:50–05:10 (good, 3.33 h)	87.1° 06:35	7.49	92%	76.1°
2028-04-12 Wed	61	—	unknown	01:05–05:05 (good, 4.0 h)	87.1° 06:30	7.44	85%	71.0°
2028-04-13 Thu	75	—	unknown	00:35–05:05 (good, 4.5 h)	87.1° 06:30	7.38	76%	66.9°
2028-04-14 Fri	87	—	unknown	00:30–05:05 (good, 4.58 h)	87.1° 06:25	7.32	67%	64.1°
2028-04-15 Sat	92	—	unknown	00:25–05:00 (good, 4.58 h)	87.1° 06:20	7.26	57%	62.6°
2028-04-16 Sun	97	—	unknown	00:20–05:00 (good, 4.67 h)	87.1° 06:15	7.21	48%	62.6°
2028-04-17 Mon	100	—	unknown	00:20–04:55 (good, 4.58 h)	87.1° 06:10	7.15	38%	63.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-03-19&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.