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: 04-13 (100), 04-14 (100), 04-15 (100), 04-16 (100), 04-17 (100) — by astronomy; check the weather when the night is within four days.

2034-04-09astronomy score per night — click a bar for that night2034-05-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-04-09 Sun	61	—	unknown	01:15–05:15 (good, 4.0 h)	87.1° 06:45	7.63	70%	58.1°
2034-04-10 Mon	80	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:40	7.58	60%	56.7°
2034-04-11 Tue	90	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:35	7.52	50%	56.9°
2034-04-12 Wed	96	—	unknown	00:40–05:10 (good, 4.5 h)	87.1° 06:35	7.46	40%	59.1°
2034-04-13 Thu	100	—	unknown	00:35–05:05 (good, 4.5 h)	87.1° 06:30	7.4	30%	63.0°
2034-04-14 Fri	100	—	unknown	00:30–05:05 (good, 4.58 h)	87.1° 06:25	7.35	20%	68.4°
2034-04-15 Sat	100	—	unknown	00:25–05:00 (good, 4.58 h)	87.1° 06:20	7.29	12%	75.2°
2034-04-16 Sun	100	—	unknown	00:25–05:00 (good, 4.58 h)	87.1° 06:20	7.23	5%	82.9°
2034-04-17 Mon	100	—	unknown	00:20–05:00 (good, 4.67 h)	87.1° 06:15	7.17	1%	91.1°
2034-04-18 Tue	100	—	unknown	00:15–04:55 (good, 4.67 h)	87.1° 06:10	7.12	0%	99.4°
2034-04-19 Wed	100	—	unknown	00:10–04:55 (good, 4.75 h)	87.1° 06:05	7.06	2%	107.2°
2034-04-20 Thu	100	—	unknown	00:10–04:50 (good, 4.67 h)	87.1° 06:00	7.0	7%	114.0°
2034-04-21 Fri	100	—	unknown	00:05–04:50 (good, 4.75 h)	87.1° 06:00	6.94	14%	119.2°
2034-04-22 Sat	100	—	unknown	00:00–04:50 (good, 4.83 h)	87.1° 05:55	6.88	23%	122.4°
2034-04-23 Sun	100	—	unknown	00:00–04:45 (good, 4.75 h)	87.1° 05:50	6.83	33%	123.4°
2034-04-24 Mon	100	—	unknown	23:55–04:45 (good, 4.83 h)	87.1° 05:45	6.77	44%	122.2°
2034-04-25 Tue	100	—	unknown	23:55–04:40 (good, 4.75 h)	87.1° 05:40	6.71	55%	119.2°
2034-04-26 Wed	100	—	unknown	23:55–04:40 (good, 4.75 h)	87.1° 05:40	6.65	65%	114.8°
2034-04-27 Thu	100	—	unknown	23:55–04:40 (good, 4.75 h)	87.1° 05:35	6.59	74%	109.4°
2034-04-28 Fri	100	—	unknown	00:00–04:35 (good, 4.58 h)	87.1° 05:30	6.53	82%	103.4°
2034-04-29 Sat	85	—	unknown	00:00–04:35 (good, 4.58 h)	87.1° 05:25	6.48	89%	97.0°
2034-04-30 Sun	80	—	unknown	00:40–04:35 (good, 3.92 h)	87.1° 05:25	6.42	94%	90.5°
2034-05-01 Mon	69	—	unknown	01:15–04:30 (good, 3.25 h)	87.1° 05:20	6.36	98%	84.0°
2034-05-02 Tue	62	—	unknown	01:50–04:30 (good, 2.67 h)	87.1° 05:15	6.3	100%	77.7°
2034-05-03 Wed	56	—	unknown	02:20–04:30 (good, 2.17 h)	87.1° 05:10	6.24	100%	71.8°
2034-05-04 Thu	52	—	unknown	03:15–04:25 (good, 1.17 h)	87.1° 05:05	6.19	98%	66.5°
2034-05-05 Fri	52	—	unknown	04:10–04:25 (good, 0.25 h)	87.1° 05:05	6.13	95%	62.1°
2034-05-06 Sat	56	—	unknown	01:30–04:20 (good, 2.83 h)	87.1° 05:00	6.07	90%	58.8°
2034-05-07 Sun	82	—	unknown	23:00–04:20 (good, 5.33 h)	87.1° 04:55	6.02	83%	57.0°
2034-05-08 Mon	88	—	unknown	22:55–04:20 (good, 5.42 h)	87.1° 04:50	5.96	75%	56.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-04-09&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.