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: 01-11 (20), 01-10 (18), 01-09 (17), 01-08 (16), 12-13 (15) — by astronomy; check the weather when the night is within four days.

2029-12-13astronomy score per night — click a bar for that night2030-01-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-12-13 Thu	15	—	unknown	18:35–19:00 (good, 0.42 h)	87.1° 13:30	11.48	61%	80.7°
2029-12-14 Fri	14	—	unknown	18:35–18:50 (good, 0.25 h)	87.1° 13:25	11.49	70%	86.6°
2029-12-15 Sat	13	—	unknown	18:35–18:45 (good, 0.17 h)	87.1° 13:20	11.49	79%	92.6°
2029-12-16 Sun	13	—	unknown	18:35–18:50 (good, 0.25 h)	87.1° 13:15	11.5	86%	98.5°
2029-12-17 Mon	13	—	unknown	18:35–18:50 (good, 0.25 h)	87.1° 13:15	11.5	92%	104.2°
2029-12-18 Tue	14	—	unknown	18:35–18:50 (good, 0.25 h)	87.1° 13:10	11.5	96%	109.3°
2029-12-19 Wed	14	—	unknown	18:35–18:50 (good, 0.25 h)	87.1° 13:05	11.51	99%	113.8°
2029-12-20 Thu	14	—	unknown	18:35–18:50 (good, 0.25 h)	87.1° 13:00	11.51	100%	117.4°
2029-12-21 Fri	13	—	unknown	18:35–18:45 (good, 0.17 h)	87.1° 13:00	11.51	99%	119.7°
2029-12-22 Sat	14	—	unknown	18:35–18:45 (good, 0.17 h)	87.1° 12:55	11.51	96%	120.4°
2029-12-23 Sun	12	—	unknown	18:40–18:50 (good, 0.17 h)	87.1° 12:50	11.51	91%	119.6°
2029-12-24 Mon	11	—	unknown	18:40–18:45 (good, 0.08 h)	87.1° 12:45	11.5	84%	117.1°
2029-12-25 Tue	11	—	unknown	18:05–19:15 (marginal, 1.17 h)	87.1° 12:40	11.5	76%	113.1°
2029-12-26 Wed	10	—	unknown	18:40–19:10 (marginal, 0.5 h)	87.1° 12:40	11.49	66%	107.9°
2029-12-27 Thu	9	—	unknown	18:40–19:05 (marginal, 0.42 h)	87.1° 12:35	11.49	55%	101.7°
2029-12-28 Fri	9	—	unknown	18:40–19:00 (marginal, 0.33 h)	87.1° 12:30	11.48	44%	94.9°
2029-12-29 Sat	8	—	unknown	18:40–18:55 (marginal, 0.25 h)	87.1° 12:25	11.48	33%	87.7°
2029-12-30 Sun	8	—	unknown	05:50–06:10 (marginal, 0.33 h)	87.1° 12:20	11.47	23%	80.6°
2029-12-31 Mon	8	—	unknown	05:50–06:10 (marginal, 0.33 h)	87.1° 12:20	11.46	14%	73.8°
2030-01-01 Tue	9	—	unknown	05:45–06:10 (marginal, 0.42 h)	87.1° 12:15	11.45	6%	67.8°
2030-01-02 Wed	10	—	unknown	05:40–06:45 (marginal, 1.08 h)	87.1° 12:10	11.44	2%	63.2°
2030-01-03 Thu	11	—	unknown	05:35–06:45 (marginal, 1.17 h)	87.1° 12:05	11.43	0%	60.4°
2030-01-04 Fri	11	—	unknown	06:05–06:10 (good, 0.08 h)	87.1° 12:00	11.42	1%	59.6°
2030-01-05 Sat	12	—	unknown	06:00–06:10 (good, 0.17 h)	87.1° 11:55	11.4	4%	60.8°
2030-01-06 Sun	13	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:50	11.39	10%	63.7°
2030-01-07 Mon	14	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:45	11.37	17%	68.0°
2030-01-08 Tue	16	—	unknown	05:50–06:10 (good, 0.33 h)	87.1° 11:45	11.36	25%	73.2°
2030-01-09 Wed	17	—	unknown	05:45–06:10 (good, 0.42 h)	87.1° 11:40	11.34	34%	78.8°
2030-01-10 Thu	18	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:35	11.32	44%	84.8°
2030-01-11 Fri	20	—	unknown	05:35–06:10 (good, 0.58 h)	87.1° 11:30	11.3	53%	90.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-12-13&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.