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: 12-10 (29), 12-11 (29), 12-12 (27), 12-13 (26), 12-08 (25) — by astronomy; check the weather when the night is within four days.

2041-12-05astronomy score per night — click a bar for that night2042-01-03

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-12-05 Thu	23	—	unknown	18:35–19:35 (good, 1.0 h)	87.1° 14:00	11.4	96%	104.8°
2041-12-06 Fri	24	—	unknown	18:35–19:35 (good, 1.0 h)	87.1° 13:55	11.41	99%	108.7°
2041-12-07 Sat	24	—	unknown	18:35–19:35 (good, 1.0 h)	87.1° 13:55	11.42	100%	111.6°
2041-12-08 Sun	25	—	unknown	18:35–19:35 (good, 1.0 h)	87.1° 13:50	11.44	98%	113.2°
2041-12-09 Mon	25	—	unknown	18:35–19:30 (good, 0.92 h)	87.1° 13:45	11.45	94%	113.5°
2041-12-10 Tue	29	—	unknown	18:35–19:30 (good, 0.92 h)	87.1° 13:40	11.46	89%	112.5°
2041-12-11 Wed	29	—	unknown	18:35–19:35 (good, 1.0 h)	87.1° 13:35	11.47	82%	110.4°
2041-12-12 Thu	27	—	unknown	18:35–19:35 (good, 1.0 h)	87.1° 13:35	11.47	74%	107.5°
2041-12-13 Fri	26	—	unknown	18:35–19:30 (good, 0.92 h)	87.1° 13:30	11.48	65%	103.9°
2041-12-14 Sat	25	—	unknown	18:35–19:25 (good, 0.83 h)	87.1° 13:25	11.49	56%	99.7°
2041-12-15 Sun	23	—	unknown	18:35–19:20 (good, 0.75 h)	87.1° 13:20	11.49	47%	95.3°
2041-12-16 Mon	23	—	unknown	18:35–19:15 (good, 0.67 h)	87.1° 13:15	11.5	37%	90.6°
2041-12-17 Tue	22	—	unknown	18:35–19:15 (good, 0.67 h)	87.1° 13:15	11.5	28%	85.8°
2041-12-18 Wed	20	—	unknown	18:35–19:10 (good, 0.58 h)	87.1° 13:10	11.5	20%	81.1°
2041-12-19 Thu	19	—	unknown	18:35–19:05 (good, 0.5 h)	87.1° 13:05	11.51	13%	76.7°
2041-12-20 Fri	18	—	unknown	18:35–19:00 (good, 0.42 h)	87.1° 13:00	11.51	7%	72.7°
2041-12-21 Sat	16	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 13:00	11.51	2%	69.5°
2041-12-22 Sun	15	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 12:55	11.51	0%	67.3°
2041-12-23 Mon	13	—	unknown	18:40–18:50 (good, 0.17 h)	87.1° 12:50	11.51	1%	66.5°
2041-12-24 Tue	12	—	unknown	18:40–18:45 (good, 0.08 h)	87.1° 12:45	11.5	3%	67.1°
2041-12-25 Wed	11	—	unknown	18:05–19:15 (marginal, 1.17 h)	87.1° 12:40	11.5	9%	69.1°
2041-12-26 Thu	10	—	unknown	18:40–19:10 (marginal, 0.5 h)	87.1° 12:40	11.49	16%	72.5°
2041-12-27 Fri	9	—	unknown	18:40–19:05 (marginal, 0.42 h)	87.1° 12:35	11.49	26%	76.9°
2041-12-28 Sat	8	—	unknown	18:40–19:00 (marginal, 0.33 h)	87.1° 12:30	11.48	36%	82.1°
2041-12-29 Sun	7	—	unknown	05:55–06:10 (marginal, 0.25 h)	87.1° 12:25	11.48	48%	87.6°
2041-12-30 Mon	8	—	unknown	05:50–06:10 (marginal, 0.33 h)	87.1° 12:20	11.47	59%	93.2°
2041-12-31 Tue	8	—	unknown	05:50–06:10 (marginal, 0.33 h)	87.1° 12:20	11.46	70%	98.5°
2042-01-01 Wed	9	—	unknown	05:45–06:10 (marginal, 0.42 h)	87.1° 12:15	11.45	79%	103.4°
2042-01-02 Thu	10	—	unknown	05:40–06:45 (marginal, 1.08 h)	87.1° 12:10	11.44	87%	107.6°
2042-01-03 Fri	9	—	unknown	05:35–06:45 (marginal, 1.17 h)	87.1° 12:05	11.43	94%	110.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-12-05&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.