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: 03-28 (100), 03-29 (100), 03-30 (100), 03-31 (100), 04-01 (100) — by astronomy; check the weather when the night is within four days.

2028-03-28astronomy score per night — click a bar for that night2028-04-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2028-04-18 Tue	100	—	unknown	00:15–04:55 (good, 4.67 h)	87.1° 06:10	7.09	29%	66.2°
2028-04-19 Wed	100	—	unknown	00:10–04:55 (good, 4.75 h)	87.1° 06:05	7.03	21%	69.5°
2028-04-20 Thu	100	—	unknown	00:05–04:50 (good, 4.75 h)	87.1° 06:00	6.97	14%	73.8°
2028-04-21 Fri	100	—	unknown	00:00–04:50 (good, 4.83 h)	87.1° 05:55	6.92	8%	78.6°
2028-04-22 Sat	100	—	unknown	00:00–04:45 (good, 4.75 h)	87.1° 05:50	6.86	4%	84.0°
2028-04-23 Sun	100	—	unknown	23:55–04:45 (good, 4.83 h)	87.1° 05:50	6.8	1%	89.6°
2028-04-24 Mon	100	—	unknown	23:50–04:45 (good, 4.92 h)	87.1° 05:45	6.74	0%	95.4°
2028-04-25 Tue	100	—	unknown	23:45–04:40 (good, 4.92 h)	87.1° 05:40	6.68	1%	101.1°
2028-04-26 Wed	100	—	unknown	23:40–04:40 (good, 5.0 h)	87.1° 05:35	6.62	5%	106.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-03-28&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.