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: 04-03 (100), 04-04 (100), 04-05 (100), 04-06 (100), 04-07 (100) — by astronomy; check the weather when the night is within four days.

2035-03-20astronomy score per night — click a bar for that night2035-04-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-03-20 Tue	78	—	unknown	01:25–04:55 (good, 3.5 h)	87.1° 07:05	8.73	90%	113.8°
2035-03-21 Wed	71	—	unknown	01:30–04:50 (good, 3.33 h)	87.1° 07:00	8.68	96%	107.9°
2035-03-22 Thu	63	—	unknown	01:35–04:50 (good, 3.25 h)	87.1° 06:55	8.63	99%	101.3°
2035-03-23 Fri	56	—	unknown	02:05–04:45 (good, 2.67 h)	87.1° 06:55	8.58	100%	94.3°
2035-03-24 Sat	50	—	unknown	02:35–05:45 (good, 2.17 h)	87.1° 07:50	8.52	99%	87.3°
2035-03-25 Sun	47	—	unknown	04:00–05:45 (good, 1.75 h)	87.1° 07:45	8.47	96%	80.6°
2035-03-26 Mon	45	—	unknown	04:05–05:40 (good, 1.58 h)	87.1° 07:40	8.42	91%	74.3°
2035-03-27 Tue	46	—	unknown	03:50–05:40 (good, 1.83 h)	87.1° 07:35	8.36	85%	68.7°
2035-03-28 Wed	49	—	unknown	03:00–05:40 (good, 2.67 h)	87.1° 07:35	8.31	77%	64.0°
2035-03-29 Thu	54	—	unknown	02:05–05:35 (good, 3.5 h)	87.1° 07:30	8.26	69%	60.3°
2035-03-30 Fri	66	—	unknown	01:30–05:35 (good, 4.08 h)	87.1° 07:25	8.2	60%	58.0°
2035-03-31 Sat	79	—	unknown	01:25–05:30 (good, 4.08 h)	87.1° 07:20	8.15	50%	57.1°
2035-04-01 Sun	91	—	unknown	01:25–05:30 (good, 4.08 h)	87.1° 07:20	8.09	41%	57.9°
2035-04-02 Mon	97	—	unknown	01:20–05:30 (good, 4.17 h)	87.1° 07:15	8.04	31%	60.2°
2035-04-03 Tue	100	—	unknown	01:15–05:25 (good, 4.17 h)	87.1° 07:10	7.98	22%	64.1°
2035-04-04 Wed	100	—	unknown	01:10–05:25 (good, 4.25 h)	87.1° 07:05	7.93	14%	69.2°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-03-20&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.