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: 04-18 (100), 04-19 (100), 04-20 (100), 04-21 (100), 04-22 (100) — by astronomy; check the weather when the night is within four days.

2047-04-07astronomy score per night — click a bar for that night2047-05-06

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-04-07 Sun	86	—	unknown	01:20–05:20 (good, 4.0 h)	87.1° 06:55	7.75	91%	108.4°
2047-04-08 Mon	78	—	unknown	01:25–05:15 (good, 3.83 h)	87.1° 06:50	7.7	96%	102.4°
2047-04-09 Tue	70	—	unknown	01:35–05:15 (good, 3.67 h)	87.1° 06:45	7.64	99%	95.6°
2047-04-10 Wed	63	—	unknown	02:00–05:10 (good, 3.17 h)	87.1° 06:40	7.58	99%	88.4°
2047-04-11 Thu	59	—	unknown	02:10–05:10 (good, 3.0 h)	87.1° 06:40	7.53	96%	81.3°
2047-04-12 Fri	58	—	unknown	01:50–05:10 (good, 3.33 h)	87.1° 06:35	7.47	91%	74.8°
2047-04-13 Sat	61	—	unknown	01:05–05:05 (good, 4.0 h)	87.1° 06:30	7.41	83%	69.3°
2047-04-14 Sun	78	—	unknown	00:30–05:05 (good, 4.58 h)	87.1° 06:25	7.36	73%	65.2°
2047-04-15 Mon	88	—	unknown	00:30–05:00 (good, 4.5 h)	87.1° 06:25	7.3	63%	62.6°
2047-04-16 Tue	94	—	unknown	00:25–05:00 (good, 4.58 h)	87.1° 06:20	7.24	52%	61.7°
2047-04-17 Wed	98	—	unknown	00:20–05:00 (good, 4.67 h)	87.1° 06:15	7.18	42%	62.5°
2047-04-18 Thu	100	—	unknown	00:15–04:55 (good, 4.67 h)	87.1° 06:10	7.12	32%	64.6°
2047-04-19 Fri	100	—	unknown	00:15–04:55 (good, 4.67 h)	87.1° 06:05	7.07	23%	67.9°
2047-04-20 Sat	100	—	unknown	00:10–04:50 (good, 4.67 h)	87.1° 06:05	7.01	16%	72.1°
2047-04-21 Sun	100	—	unknown	00:05–04:50 (good, 4.75 h)	87.1° 06:00	6.95	10%	77.0°
2047-04-22 Mon	100	—	unknown	00:00–04:50 (good, 4.83 h)	87.1° 05:55	6.89	5%	82.2°
2047-04-23 Tue	100	—	unknown	23:55–04:45 (good, 4.83 h)	87.1° 05:50	6.83	2%	87.8°
2047-04-24 Wed	100	—	unknown	23:55–04:45 (good, 4.83 h)	87.1° 05:45	6.78	0%	93.4°
2047-04-25 Thu	100	—	unknown	23:50–04:45 (good, 4.92 h)	87.1° 05:45	6.72	1%	98.9°
2047-04-26 Fri	100	—	unknown	23:45–04:40 (good, 4.92 h)	87.1° 05:40	6.66	3%	104.1°
2047-04-27 Sat	100	—	unknown	23:40–04:40 (good, 5.0 h)	87.1° 05:35	6.6	7%	108.8°
2047-04-28 Sun	100	—	unknown	23:40–04:35 (good, 4.92 h)	87.1° 05:30	6.54	12%	112.9°
2047-04-29 Mon	100	—	unknown	23:35–04:35 (good, 5.0 h)	87.1° 05:30	6.48	19%	116.0°
2047-04-30 Tue	100	—	unknown	23:30–04:35 (good, 5.08 h)	87.1° 05:25	6.43	28%	117.9°
2047-05-01 Wed	100	—	unknown	23:30–04:30 (good, 5.0 h)	87.1° 05:20	6.37	37%	118.4°
2047-05-02 Thu	100	—	unknown	23:30–04:30 (good, 5.0 h)	87.1° 05:15	6.31	48%	117.4°
2047-05-03 Fri	100	—	unknown	23:25–04:30 (good, 5.08 h)	87.1° 05:10	6.25	58%	114.7°
2047-05-04 Sat	100	—	unknown	23:25–04:25 (good, 5.0 h)	87.1° 05:10	6.19	69%	110.6°
2047-05-05 Sun	100	—	unknown	23:30–04:25 (good, 4.92 h)	87.1° 05:05	6.14	79%	105.2°
2047-05-06 Mon	100	—	unknown	23:30–04:20 (good, 4.83 h)	87.1° 05:00	6.08	88%	98.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-04-07&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.