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: 04-05 (100), 04-06 (100), 04-07 (100), 04-08 (100), 04-09 (100) — by astronomy; check the weather when the night is within four days.

2035-04-05astronomy score per night — click a bar for that night2035-05-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-04-05 Thu	100	—	unknown	01:10–05:20 (good, 4.17 h)	87.1° 07:00	7.87	8%	75.4°
2035-04-06 Fri	100	—	unknown	01:05–05:20 (good, 4.25 h)	87.1° 07:00	7.82	3%	82.5°
2035-04-07 Sat	100	—	unknown	01:00–05:20 (good, 4.33 h)	87.1° 06:55	7.76	0%	90.0°
2035-04-08 Sun	100	—	unknown	00:55–05:15 (good, 4.33 h)	87.1° 06:50	7.7	0%	97.7°
2035-04-09 Mon	100	—	unknown	00:50–05:15 (good, 4.42 h)	87.1° 06:45	7.65	3%	105.2°
2035-04-10 Tue	100	—	unknown	00:50–05:10 (good, 4.33 h)	87.1° 06:40	7.59	8%	111.9°
2035-04-11 Wed	100	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:40	7.53	16%	117.4°
2035-04-12 Thu	100	—	unknown	00:40–05:10 (good, 4.5 h)	87.1° 06:35	7.48	26%	121.1°
2035-04-13 Fri	100	—	unknown	00:40–05:05 (good, 4.42 h)	87.1° 06:30	7.42	37%	122.7°
2035-04-14 Sat	100	—	unknown	00:35–05:05 (good, 4.5 h)	87.1° 06:25	7.36	48%	122.1°
2035-04-15 Sun	100	—	unknown	00:35–05:00 (good, 4.42 h)	87.1° 06:25	7.3	59%	119.4°
2035-04-16 Mon	100	—	unknown	00:35–05:00 (good, 4.42 h)	87.1° 06:20	7.25	70%	115.0°
2035-04-17 Tue	100	—	unknown	00:35–05:00 (good, 4.42 h)	87.1° 06:15	7.19	79%	109.4°
2035-04-18 Wed	87	—	unknown	00:40–04:55 (good, 4.25 h)	87.1° 06:10	7.13	87%	103.1°
2035-04-19 Thu	79	—	unknown	00:55–04:55 (good, 4.0 h)	87.1° 06:05	7.07	93%	96.3°
2035-04-20 Fri	70	—	unknown	01:35–04:55 (good, 3.33 h)	87.1° 06:05	7.01	97%	89.5°
2035-04-21 Sat	61	—	unknown	02:15–04:50 (good, 2.58 h)	87.1° 06:00	6.96	100%	82.7°
2035-04-22 Sun	54	—	unknown	02:45–04:50 (good, 2.08 h)	87.1° 05:55	6.9	100%	76.3°
2035-04-23 Mon	50	—	unknown	03:05–04:45 (good, 1.67 h)	87.1° 05:50	6.84	98%	70.5°
2035-04-24 Tue	49	—	unknown	03:05–04:45 (good, 1.67 h)	87.1° 05:45	6.78	94%	65.5°
2035-04-25 Wed	51	—	unknown	02:35–04:45 (good, 2.17 h)	87.1° 05:45	6.72	90%	61.5°
2035-04-26 Thu	58	—	unknown	00:50–04:40 (good, 3.83 h)	87.1° 05:40	6.67	83%	58.7°
2035-04-27 Fri	83	—	unknown	23:40–04:40 (good, 5.0 h)	87.1° 05:35	6.61	75%	57.4°
2035-04-28 Sat	89	—	unknown	23:35–04:35 (good, 5.0 h)	87.1° 05:30	6.55	67%	57.6°
2035-04-29 Sun	94	—	unknown	23:35–04:35 (good, 5.0 h)	87.1° 05:30	6.49	57%	59.4°
2035-04-30 Mon	100	—	unknown	23:30–04:35 (good, 5.08 h)	87.1° 05:25	6.43	48%	62.7°
2035-05-01 Tue	100	—	unknown	23:25–04:30 (good, 5.08 h)	87.1° 05:20	6.37	38%	67.3°
2035-05-02 Wed	100	—	unknown	23:20–04:30 (good, 5.17 h)	87.1° 05:15	6.32	28%	73.0°
2035-05-03 Thu	100	—	unknown	23:20–04:30 (good, 5.17 h)	87.1° 05:10	6.26	19%	79.6°
2035-05-04 Fri	100	—	unknown	23:15–04:25 (good, 5.17 h)	87.1° 05:10	6.2	11%	86.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-04-05&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.