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), 04-09 (100), 04-10 (100), 04-11 (100) — by astronomy; check the weather when the night is within four days.

2037-03-22astronomy score per night — click a bar for that night2037-04-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-03-22 Sun	99	—	unknown	01:00–04:50 (good, 3.83 h)	87.1° 06:55	8.6	31%	116.8°
2037-03-23 Mon	100	—	unknown	01:00–04:45 (good, 3.75 h)	87.1° 06:50	8.55	41%	119.5°
2037-03-24 Tue	100	—	unknown	01:00–04:45 (good, 3.75 h)	87.1° 06:45	8.5	52%	120.4°
2037-03-25 Wed	99	—	unknown	00:55–04:40 (good, 3.75 h)	87.1° 06:45	8.44	63%	119.5°
2037-03-26 Thu	96	—	unknown	00:55–04:40 (good, 3.75 h)	87.1° 06:40	8.39	73%	116.7°
2037-03-27 Fri	93	—	unknown	00:55–04:40 (good, 3.75 h)	87.1° 06:35	8.34	83%	112.1°
2037-03-28 Sat	76	—	unknown	01:00–05:35 (good, 3.58 h)	87.1° 07:30	8.28	91%	106.1°
2037-03-29 Sun	67	—	unknown	02:10–05:35 (good, 3.42 h)	87.1° 07:30	8.23	97%	99.1°
2037-03-30 Mon	58	—	unknown	02:55–05:35 (good, 2.67 h)	87.1° 07:25	8.17	100%	91.6°
2037-03-31 Tue	50	—	unknown	03:30–05:30 (good, 2.0 h)	87.1° 07:20	8.12	99%	84.0°
2037-04-01 Wed	47	—	unknown	03:55–05:30 (good, 1.58 h)	87.1° 07:15	8.06	96%	76.9°
2037-04-02 Thu	45	—	unknown	03:50–05:25 (good, 1.58 h)	87.1° 07:10	8.01	91%	70.6°
2037-04-03 Fri	49	—	unknown	03:10–05:25 (good, 2.25 h)	87.1° 07:10	7.95	84%	65.6°
2037-04-04 Sat	55	—	unknown	01:40–05:25 (good, 3.75 h)	87.1° 07:05	7.9	75%	62.0°
2037-04-05 Sun	71	—	unknown	01:05–05:20 (good, 4.25 h)	87.1° 07:00	7.84	65%	60.0°
2037-04-06 Mon	85	—	unknown	01:00–05:20 (good, 4.33 h)	87.1° 06:55	7.79	55%	59.8°
2037-04-07 Tue	93	—	unknown	01:00–05:15 (good, 4.25 h)	87.1° 06:50	7.73	46%	61.0°
2037-04-08 Wed	99	—	unknown	00:55–05:15 (good, 4.33 h)	87.1° 06:50	7.67	36%	63.7°
2037-04-09 Thu	100	—	unknown	00:50–05:15 (good, 4.42 h)	87.1° 06:45	7.62	27%	67.4°
2037-04-10 Fri	100	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:40	7.56	19%	72.0°
2037-04-11 Sat	100	—	unknown	00:40–05:10 (good, 4.5 h)	87.1° 06:35	7.5	12%	77.2°
2037-04-12 Sun	100	—	unknown	00:40–05:05 (good, 4.42 h)	87.1° 06:35	7.45	7%	82.9°
2037-04-13 Mon	100	—	unknown	00:35–05:05 (good, 4.5 h)	87.1° 06:30	7.39	3%	88.9°
2037-04-14 Tue	100	—	unknown	00:30–05:05 (good, 4.58 h)	87.1° 06:25	7.33	1%	95.0°
2037-04-15 Wed	100	—	unknown	00:25–05:00 (good, 4.58 h)	87.1° 06:20	7.27	0%	100.9°
2037-04-16 Thu	100	—	unknown	00:25–05:00 (good, 4.58 h)	87.1° 06:15	7.22	2%	106.6°
2037-04-17 Fri	100	—	unknown	00:20–04:55 (good, 4.58 h)	87.1° 06:15	7.16	5%	111.6°
2037-04-18 Sat	100	—	unknown	00:15–04:55 (good, 4.67 h)	87.1° 06:10	7.1	11%	115.8°
2037-04-19 Sun	100	—	unknown	00:10–04:55 (good, 4.75 h)	87.1° 06:05	7.04	18%	118.7°
2037-04-20 Mon	100	—	unknown	00:10–04:50 (good, 4.67 h)	87.1° 06:00	6.98	27%	120.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-03-22&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.