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: 01-18 (27), 01-17 (26), 01-19 (26), 01-16 (25), 01-15 (24) — by astronomy; check the weather when the night is within four days.

2045-12-22astronomy score per night — click a bar for that night2046-01-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-12-22 Fri	10	—	unknown	18:05–19:25 (marginal, 1.33 h)	87.1° 12:55	11.51	98%	110.4°
2045-12-23 Sat	9	—	unknown	18:40–19:20 (marginal, 0.67 h)	87.1° 12:50	11.5	100%	113.8°
2045-12-24 Sun	9	—	unknown	18:40–19:15 (marginal, 0.58 h)	87.1° 12:45	11.5	99%	115.8°
2045-12-25 Mon	10	—	unknown	18:05–19:15 (marginal, 1.17 h)	87.1° 12:40	11.5	95%	116.0°
2045-12-26 Tue	10	—	unknown	18:40–19:10 (marginal, 0.5 h)	87.1° 12:40	11.49	89%	114.4°
2045-12-27 Wed	9	—	unknown	18:40–19:05 (marginal, 0.42 h)	87.1° 12:35	11.49	80%	111.2°
2045-12-28 Thu	9	—	unknown	18:40–19:00 (marginal, 0.33 h)	87.1° 12:30	11.48	70%	106.7°
2045-12-29 Fri	8	—	unknown	18:40–18:55 (marginal, 0.25 h)	87.1° 12:25	11.48	59%	101.4°
2045-12-30 Sat	8	—	unknown	05:50–06:10 (marginal, 0.33 h)	87.1° 12:20	11.47	48%	95.5°
2045-12-31 Sun	7	—	unknown	05:50–06:10 (marginal, 0.33 h)	87.1° 12:20	11.46	37%	89.5°
2046-01-01 Mon	8	—	unknown	05:45–06:10 (marginal, 0.42 h)	87.1° 12:15	11.45	27%	83.6°
2046-01-02 Tue	9	—	unknown	05:40–06:10 (marginal, 0.5 h)	87.1° 12:10	11.44	18%	78.1°
2046-01-03 Wed	11	—	unknown	05:35–06:45 (marginal, 1.17 h)	87.1° 12:05	11.43	11%	73.2°
2046-01-04 Thu	11	—	unknown	06:05–06:10 (good, 0.08 h)	87.1° 12:00	11.41	5%	69.1°
2046-01-05 Fri	12	—	unknown	06:00–06:10 (good, 0.17 h)	87.1° 11:55	11.4	2%	66.1°
2046-01-06 Sat	13	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:50	11.39	0%	64.3°
2046-01-07 Sun	14	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:45	11.37	1%	63.9°
2046-01-08 Mon	16	—	unknown	05:50–06:10 (good, 0.33 h)	87.1° 11:45	11.36	3%	64.6°
2046-01-09 Tue	17	—	unknown	05:45–06:10 (good, 0.42 h)	87.1° 11:40	11.34	7%	66.6°
2046-01-10 Wed	18	—	unknown	05:40–06:10 (good, 0.5 h)	87.1° 11:35	11.32	12%	69.5°
2046-01-11 Thu	20	—	unknown	05:35–06:10 (good, 0.58 h)	87.1° 11:30	11.3	19%	73.3°
2046-01-12 Fri	21	—	unknown	05:35–06:10 (good, 0.58 h)	87.1° 11:25	11.28	27%	77.7°
2046-01-13 Sat	22	—	unknown	05:30–06:10 (good, 0.67 h)	87.1° 11:25	11.26	36%	82.6°
2046-01-14 Sun	23	—	unknown	05:25–06:10 (good, 0.75 h)	87.1° 11:20	11.24	45%	87.8°
2046-01-15 Mon	24	—	unknown	05:20–06:10 (good, 0.83 h)	87.1° 11:15	11.22	55%	93.2°
2046-01-16 Tue	25	—	unknown	05:15–06:10 (good, 0.92 h)	87.1° 11:10	11.2	65%	98.6°
2046-01-17 Wed	26	—	unknown	05:15–06:10 (good, 0.92 h)	87.1° 11:10	11.18	75%	103.8°
2046-01-18 Thu	27	—	unknown	05:10–06:10 (good, 1.0 h)	87.1° 11:05	11.15	83%	108.5°
2046-01-19 Fri	26	—	unknown	05:15–06:10 (good, 0.92 h)	87.1° 11:00	11.13	91%	112.4°
2046-01-20 Sat	24	—	unknown	05:15–06:10 (good, 0.92 h)	87.1° 10:55	11.1	96%	115.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-12-22&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.