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: 04-25 (100), 04-26 (100), 04-27 (100), 04-28 (100), 05-11 (100) — by astronomy; check the weather when the night is within four days.

2034-04-25astronomy score per night — click a bar for that night2034-05-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2034-05-09 Tue	94	—	unknown	22:55–04:15 (good, 5.33 h)	87.1° 04:45	5.9	66%	58.4°
2034-05-10 Wed	99	—	unknown	22:50–04:15 (good, 5.42 h)	87.1° 04:45	5.85	56%	61.7°
2034-05-11 Thu	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 04:40	5.79	45%	66.5°
2034-05-12 Fri	100	—	unknown	22:40–04:10 (good, 5.5 h)	87.1° 04:35	5.74	34%	72.7°
2034-05-13 Sat	100	—	unknown	22:35–04:10 (good, 5.58 h)	87.1° 04:30	5.68	24%	79.8°
2034-05-14 Sun	100	—	unknown	22:35–04:10 (good, 5.58 h)	87.1° 04:30	5.63	15%	87.6°
2034-05-15 Mon	100	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:25	5.57	7%	95.8°
2034-05-16 Tue	100	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:20	5.52	2%	103.7°
2034-05-17 Wed	100	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:15	5.47	0%	111.0°
2034-05-18 Thu	100	—	unknown	22:35–04:00 (good, 5.42 h)	87.1° 04:10	5.42	1%	117.0°
2034-05-19 Fri	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:10	5.37	5%	121.2°
2034-05-20 Sat	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:05	5.32	11%	123.1°
2034-05-21 Sun	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:00	5.27	20%	122.7°
2034-05-22 Mon	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:55	5.22	29%	120.2°
2034-05-23 Tue	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:50	5.17	39%	116.0°
2034-05-24 Wed	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:50	5.13	49%	110.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-04-25&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.