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: 05-19 (100), 05-20 (100), 05-21 (100), 05-22 (100), 05-23 (100) — by astronomy; check the weather when the night is within four days.

2029-05-19astronomy score per night — click a bar for that night2029-06-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-05-19 Sat	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:05	5.36	36%	117.8°
2029-05-20 Sun	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:05	5.31	47%	114.6°
2029-05-21 Mon	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:00	5.26	58%	109.9°
2029-05-22 Tue	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:55	5.21	70%	104.0°
2029-05-23 Wed	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:50	5.16	80%	97.2°
2029-05-24 Thu	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:45	5.11	88%	90.0°
2029-05-25 Fri	78	—	unknown	23:10–03:55 (good, 4.75 h)	87.1° 03:45	5.07	95%	82.7°
2029-05-26 Sat	71	—	unknown	23:40–03:50 (good, 4.17 h)	87.1° 03:40	5.03	99%	75.8°
2029-05-27 Sun	63	—	unknown	23:55–03:50 (good, 3.92 h)	87.1° 03:35	4.98	100%	69.7°
2029-05-28 Mon	59	—	unknown	23:20–03:50 (good, 4.5 h)	87.1° 03:30	4.94	98%	64.9°
2029-05-29 Tue	63	—	unknown	22:55–03:50 (good, 4.92 h)	87.1° 03:30	4.9	94%	61.8°
2029-05-30 Wed	91	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:25	4.86	88%	60.4°
2029-05-31 Thu	96	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:20	4.82	80%	60.9°
2029-06-01 Fri	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:15	4.79	70%	62.9°
2029-06-02 Sat	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:10	4.75	61%	66.3°
2029-06-03 Sun	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:10	4.72	51%	70.6°
2029-06-04 Mon	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:05	4.68	42%	75.6°
2029-06-05 Tue	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 03:00	4.65	32%	81.1°
2029-06-06 Wed	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:55	4.63	24%	86.8°
2029-06-07 Thu	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:50	4.6	16%	92.6°
2029-06-08 Fri	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:50	4.57	10%	98.4°
2029-06-09 Sat	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:45	4.55	5%	104.0°
2029-06-10 Sun	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:40	4.53	2%	109.2°
2029-06-11 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:35	4.51	0%	113.6°
2029-06-12 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:35	4.49	1%	117.0°
2029-06-13 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:30	4.48	3%	119.1°
2029-06-14 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:25	4.46	8%	119.6°
2029-06-15 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:20	4.45	15%	118.4°
2029-06-16 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:15	4.44	24%	115.5°
2029-06-17 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:15	4.43	34%	111.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-05-19&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.