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: 05-07 (100), 05-08 (100), 05-09 (100), 05-10 (100), 05-11 (100) — by astronomy; check the weather when the night is within four days.

2035-05-07astronomy score per night — click a bar for that night2035-06-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-05-07 Mon	100	—	unknown	23:00–04:20 (good, 5.33 h)	87.1° 04:55	6.03	0%	109.2°
2035-05-08 Tue	100	—	unknown	23:00–04:20 (good, 5.33 h)	87.1° 04:50	5.97	2%	115.4°
2035-05-09 Wed	100	—	unknown	22:55–04:15 (good, 5.33 h)	87.1° 04:50	5.92	7%	119.9°
2035-05-10 Thu	100	—	unknown	22:50–04:15 (good, 5.42 h)	87.1° 04:45	5.86	14%	122.3°
2035-05-11 Fri	100	—	unknown	22:50–04:15 (good, 5.42 h)	87.1° 04:40	5.81	23%	122.3°
2035-05-12 Sat	100	—	unknown	22:45–04:10 (good, 5.42 h)	87.1° 04:35	5.75	33%	120.1°
2035-05-13 Sun	100	—	unknown	22:45–04:10 (good, 5.42 h)	87.1° 04:35	5.7	44%	116.0°
2035-05-14 Mon	100	—	unknown	22:45–04:10 (good, 5.42 h)	87.1° 04:30	5.64	55%	110.6°
2035-05-15 Tue	100	—	unknown	22:45–04:05 (good, 5.33 h)	87.1° 04:25	5.59	66%	104.4°
2035-05-16 Wed	100	—	unknown	22:50–04:05 (good, 5.25 h)	87.1° 04:20	5.53	75%	97.8°
2035-05-17 Thu	84	—	unknown	23:05–04:05 (good, 5.0 h)	87.1° 04:15	5.48	83%	91.0°
2035-05-18 Fri	79	—	unknown	23:50–04:05 (good, 4.25 h)	87.1° 04:15	5.43	90%	84.3°
2035-05-19 Sat	72	—	unknown	00:35–04:00 (good, 3.42 h)	87.1° 04:10	5.38	95%	77.9°
2035-05-20 Sun	62	—	unknown	01:10–04:00 (good, 2.83 h)	87.1° 04:05	5.33	98%	72.0°
2035-05-21 Mon	56	—	unknown	02:40–04:00 (good, 1.33 h)	87.1° 04:00	5.28	100%	66.8°
2035-05-22 Tue	51	—	unknown	22:45–03:55 (marginal, 5.17 h)	87.1° 03:55	5.23	99%	62.5°
2035-05-23 Wed	51	—	unknown	22:45–03:55 (marginal, 5.17 h)	87.1° 03:55	5.18	97%	59.5°
2035-05-24 Thu	57	—	unknown	23:55–02:00 (good, 2.08 h)	87.1° 03:50	5.14	93%	57.8°
2035-05-25 Fri	87	—	unknown	22:50–03:55 (good, 5.08 h)	87.1° 03:45	5.09	88%	57.6°
2035-05-26 Sat	93	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:40	5.05	81%	59.0°
2035-05-27 Sun	98	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:40	5.0	73%	61.8°
2035-05-28 Mon	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:35	4.96	64%	66.0°
2035-05-29 Tue	100	—	unknown	22:55–03:50 (good, 4.92 h)	87.1° 03:30	4.92	54%	71.2°
2035-05-30 Wed	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:25	4.88	44%	77.4°
2035-05-31 Thu	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:20	4.84	33%	84.2°
2035-06-01 Fri	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:20	4.8	24%	91.5°
2035-06-02 Sat	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:15	4.77	15%	99.0°
2035-06-03 Sun	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:10	4.73	7%	106.2°
2035-06-04 Mon	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:05	4.7	2%	112.8°
2035-06-05 Tue	100	—	unknown	23:00–03:40 (good, 4.67 h)	87.1° 03:00	4.67	0%	118.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-05-07&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.