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: 12-09 (32), 12-10 (31), 12-11 (29), 12-12 (28), 12-13 (26) — by astronomy; check the weather when the night is within four days.

2047-12-09astronomy score per night — click a bar for that night2048-01-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-12-09 Mon	32	—	unknown	18:35–19:45 (good, 1.17 h)	87.1° 13:45	11.44	55%	109.3°
2047-12-10 Tue	31	—	unknown	18:35–19:40 (good, 1.08 h)	87.1° 13:45	11.45	44%	103.6°
2047-12-11 Wed	29	—	unknown	18:35–19:40 (good, 1.08 h)	87.1° 13:40	11.46	33%	97.2°
2047-12-12 Thu	28	—	unknown	18:35–19:35 (good, 1.0 h)	87.1° 13:35	11.47	22%	90.2°
2047-12-13 Fri	26	—	unknown	18:35–19:30 (good, 0.92 h)	87.1° 13:30	11.48	14%	83.1°
2047-12-14 Sat	26	—	unknown	18:35–19:25 (good, 0.83 h)	87.1° 13:25	11.48	6%	76.1°
2047-12-15 Sun	24	—	unknown	18:35–19:25 (good, 0.83 h)	87.1° 13:25	11.49	2%	69.9°
2047-12-16 Mon	23	—	unknown	18:35–19:20 (good, 0.75 h)	87.1° 13:20	11.5	0%	65.0°
2047-12-17 Tue	22	—	unknown	18:35–19:15 (good, 0.67 h)	87.1° 13:15	11.5	1%	61.7°
2047-12-18 Wed	21	—	unknown	18:35–19:10 (good, 0.58 h)	87.1° 13:10	11.5	5%	60.5°
2047-12-19 Thu	18	—	unknown	18:35–19:05 (good, 0.5 h)	87.1° 13:10	11.51	12%	61.4°
2047-12-20 Fri	16	—	unknown	18:35–18:55 (good, 0.33 h)	87.1° 13:05	11.51	20%	64.0°
2047-12-21 Sat	13	—	unknown	18:35–18:45 (good, 0.17 h)	87.1° 13:00	11.51	29%	68.0°
2047-12-22 Sun	11	—	unknown	18:35–18:40 (good, 0.08 h)	87.1° 12:55	11.51	39%	72.8°
2047-12-23 Mon	9	—	unknown	18:40–19:25 (marginal, 0.75 h)	87.1° 12:50	11.51	48%	78.3°
2047-12-24 Tue	8	—	unknown	18:40–19:20 (marginal, 0.67 h)	87.1° 12:50	11.5	58%	84.1°
2047-12-25 Wed	7	—	unknown	18:40–19:15 (marginal, 0.58 h)	87.1° 12:45	11.5	68%	89.9°
2047-12-26 Thu	7	—	unknown	18:40–19:10 (marginal, 0.5 h)	87.1° 12:40	11.5	76%	95.8°
2047-12-27 Fri	7	—	unknown	18:40–19:05 (marginal, 0.42 h)	87.1° 12:35	11.49	84%	101.4°
2047-12-28 Sat	7	—	unknown	18:40–19:05 (marginal, 0.42 h)	87.1° 12:30	11.49	90%	106.6°
2047-12-29 Sun	7	—	unknown	18:40–19:00 (marginal, 0.33 h)	87.1° 12:30	11.48	95%	111.2°
2047-12-30 Mon	6	—	unknown	05:55–06:10 (marginal, 0.25 h)	87.1° 12:25	11.47	98%	115.0°
2047-12-31 Tue	7	—	unknown	05:50–06:10 (marginal, 0.33 h)	87.1° 12:20	11.46	100%	117.8°
2048-01-01 Wed	7	—	unknown	05:45–06:10 (marginal, 0.42 h)	87.1° 12:15	11.45	100%	119.3°
2048-01-02 Thu	8	—	unknown	05:45–06:10 (marginal, 0.42 h)	87.1° 12:15	11.44	97%	119.3°
2048-01-03 Fri	8	—	unknown	05:40–06:10 (marginal, 0.5 h)	87.1° 12:10	11.43	93%	117.7°
2048-01-04 Sat	9	—	unknown	05:35–06:10 (marginal, 0.58 h)	87.1° 12:05	11.42	87%	114.7°
2048-01-05 Sun	9	—	unknown	05:30–06:10 (marginal, 0.67 h)	87.1° 12:00	11.41	79%	110.4°
2048-01-06 Mon	10	—	unknown	05:25–06:10 (marginal, 0.75 h)	87.1° 11:55	11.39	70%	105.0°
2048-01-07 Tue	10	—	unknown	05:25–06:45 (marginal, 1.33 h)	87.1° 11:50	11.38	59%	98.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-12-09&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.