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: 04-20 (100), 04-21 (100), 04-22 (100), 04-23 (100), 04-24 (100) — by astronomy; check the weather when the night is within four days.

2029-04-20astronomy score per night — click a bar for that night2029-05-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-04-20 Fri	100	—	unknown	00:10–04:50 (good, 4.67 h)	87.1° 06:00	6.99	40%	119.3°
2029-04-21 Sat	100	—	unknown	00:10–04:50 (good, 4.67 h)	87.1° 05:55	6.93	51%	119.0°
2029-04-22 Sun	100	—	unknown	00:10–04:50 (good, 4.67 h)	87.1° 05:55	6.87	62%	116.9°
2029-04-23 Mon	100	—	unknown	00:10–04:45 (good, 4.58 h)	87.1° 05:50	6.81	73%	113.2°
2029-04-24 Tue	100	—	unknown	00:10–04:45 (good, 4.58 h)	87.1° 05:45	6.75	82%	107.9°
2029-04-25 Wed	87	—	unknown	00:15–04:40 (good, 4.42 h)	87.1° 05:40	6.7	90%	101.5°
2029-04-26 Thu	82	—	unknown	00:25–04:40 (good, 4.25 h)	87.1° 05:35	6.64	96%	94.4°
2029-04-27 Fri	73	—	unknown	01:00–04:40 (good, 3.67 h)	87.1° 05:35	6.58	99%	86.9°
2029-04-28 Sat	65	—	unknown	01:20–04:35 (good, 3.25 h)	87.1° 05:30	6.52	100%	79.6°
2029-04-29 Sun	61	—	unknown	01:20–04:35 (good, 3.25 h)	87.1° 05:25	6.46	97%	73.0°
2029-04-30 Mon	63	—	unknown	00:35–04:35 (good, 4.0 h)	87.1° 05:20	6.41	91%	67.5°
2029-05-01 Tue	83	—	unknown	23:25–04:30 (good, 5.08 h)	87.1° 05:20	6.35	84%	63.5°
2029-05-02 Wed	88	—	unknown	23:20–04:30 (good, 5.17 h)	87.1° 05:15	6.29	75%	61.1°
2029-05-03 Thu	94	—	unknown	23:15–04:25 (good, 5.17 h)	87.1° 05:10	6.23	65%	60.5°
2029-05-04 Fri	98	—	unknown	23:10–04:25 (good, 5.25 h)	87.1° 05:05	6.17	55%	61.6°
2029-05-05 Sat	100	—	unknown	23:10–04:25 (good, 5.25 h)	87.1° 05:00	6.12	45%	64.1°
2029-05-06 Sun	100	—	unknown	23:05–04:20 (good, 5.25 h)	87.1° 05:00	6.06	35%	67.7°
2029-05-07 Mon	100	—	unknown	23:00–04:20 (good, 5.33 h)	87.1° 04:55	6.0	26%	72.2°
2029-05-08 Tue	100	—	unknown	22:55–04:20 (good, 5.42 h)	87.1° 04:50	5.95	19%	77.3°
2029-05-09 Wed	100	—	unknown	22:50–04:15 (good, 5.42 h)	87.1° 04:45	5.89	12%	82.8°
2029-05-10 Thu	100	—	unknown	22:50–04:15 (good, 5.42 h)	87.1° 04:40	5.83	6%	88.6°
2029-05-11 Fri	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 04:40	5.78	3%	94.4°
2029-05-12 Sat	100	—	unknown	22:40–04:10 (good, 5.5 h)	87.1° 04:35	5.72	0%	100.1°
2029-05-13 Sun	100	—	unknown	22:35–04:10 (good, 5.58 h)	87.1° 04:30	5.67	0%	105.6°
2029-05-14 Mon	100	—	unknown	22:30–04:10 (good, 5.67 h)	87.1° 04:25	5.62	2%	110.5°
2029-05-15 Tue	100	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:25	5.56	5%	114.6°
2029-05-16 Wed	100	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:20	5.51	11%	117.7°
2029-05-17 Thu	100	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:15	5.46	18%	119.3°
2029-05-18 Fri	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:10	5.41	26%	119.4°
2029-05-19 Sat	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:05	5.36	36%	117.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-04-20&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.