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: 04-10 (100), 04-11 (100), 04-12 (100), 04-13 (100), 04-14 (100) — by astronomy; check the weather when the night is within four days.

2045-04-01astronomy score per night — click a bar for that night2045-04-30

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-04-01 Sat	63	—	unknown	02:20–05:30 (good, 3.17 h)	87.1° 07:15	8.06	100%	93.5°
2045-04-02 Sun	59	—	unknown	02:30–05:25 (good, 2.92 h)	87.1° 07:10	8.01	98%	87.6°
2045-04-03 Mon	57	—	unknown	02:25–05:25 (good, 3.0 h)	87.1° 07:10	7.95	94%	82.0°
2045-04-04 Tue	58	—	unknown	01:55–05:25 (good, 3.5 h)	87.1° 07:05	7.89	88%	77.0°
2045-04-05 Wed	61	—	unknown	01:30–05:20 (good, 3.83 h)	87.1° 07:00	7.84	81%	72.6°
2045-04-06 Thu	73	—	unknown	01:00–05:20 (good, 4.33 h)	87.1° 06:55	7.78	72%	69.2°
2045-04-07 Fri	84	—	unknown	01:00–05:15 (good, 4.25 h)	87.1° 06:50	7.73	63%	66.7°
2045-04-08 Sat	93	—	unknown	00:55–05:15 (good, 4.33 h)	87.1° 06:50	7.67	54%	65.4°
2045-04-09 Sun	97	—	unknown	00:50–05:15 (good, 4.42 h)	87.1° 06:45	7.61	44%	65.2°
2045-04-10 Mon	100	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:40	7.56	35%	66.1°
2045-04-11 Tue	100	—	unknown	00:40–05:10 (good, 4.5 h)	87.1° 06:35	7.5	26%	68.1°
2045-04-12 Wed	100	—	unknown	00:40–05:05 (good, 4.42 h)	87.1° 06:35	7.44	18%	71.1°
2045-04-13 Thu	100	—	unknown	00:35–05:05 (good, 4.5 h)	87.1° 06:30	7.39	12%	74.9°
2045-04-14 Fri	100	—	unknown	00:30–05:05 (good, 4.58 h)	87.1° 06:25	7.33	6%	79.4°
2045-04-15 Sat	100	—	unknown	00:25–05:00 (good, 4.58 h)	87.1° 06:20	7.27	2%	84.5°
2045-04-16 Sun	100	—	unknown	00:25–05:00 (good, 4.58 h)	87.1° 06:15	7.21	0%	89.9°
2045-04-17 Mon	100	—	unknown	00:20–04:55 (good, 4.58 h)	87.1° 06:15	7.15	1%	95.5°
2045-04-18 Tue	100	—	unknown	00:15–04:55 (good, 4.67 h)	87.1° 06:10	7.1	3%	100.9°
2045-04-19 Wed	100	—	unknown	00:10–04:55 (good, 4.75 h)	87.1° 06:05	7.04	8%	105.8°
2045-04-20 Thu	100	—	unknown	00:10–04:50 (good, 4.67 h)	87.1° 06:00	6.98	15%	110.0°
2045-04-21 Fri	100	—	unknown	00:05–04:50 (good, 4.75 h)	87.1° 05:55	6.92	24%	113.0°
2045-04-22 Sat	100	—	unknown	00:05–04:50 (good, 4.75 h)	87.1° 05:55	6.86	35%	114.7°
2045-04-23 Sun	100	—	unknown	00:00–04:45 (good, 4.75 h)	87.1° 05:50	6.81	46%	114.8°
2045-04-24 Mon	100	—	unknown	00:00–04:45 (good, 4.75 h)	87.1° 05:45	6.75	57%	113.3°
2045-04-25 Tue	100	—	unknown	00:00–04:40 (good, 4.67 h)	87.1° 05:40	6.69	68%	110.4°
2045-04-26 Wed	100	—	unknown	00:00–04:40 (good, 4.67 h)	87.1° 05:40	6.63	78%	106.2°
2045-04-27 Thu	100	—	unknown	00:05–04:40 (good, 4.58 h)	87.1° 05:35	6.57	87%	101.2°
2045-04-28 Fri	83	—	unknown	00:10–04:35 (good, 4.42 h)	87.1° 05:30	6.51	94%	95.6°
2045-04-29 Sat	78	—	unknown	00:40–04:35 (good, 3.92 h)	87.1° 05:25	6.46	98%	89.8°
2045-04-30 Sun	71	—	unknown	00:55–04:30 (good, 3.58 h)	87.1° 05:20	6.4	100%	84.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-04-01&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.