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 Andromeda Galaxy: 01-13 (100), 01-14 (100), 01-15 (100), 01-16 (100), 01-17 (100) — by astronomy; check the weather when the night is within four days.

2047-01-09astronomy score per night — click a bar for that night2047-02-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-01-09 Wed	34	—	unknown	18:50–23:50 (marginal, 5.0 h)	89.8° 17:50	11.34	95%	60.3°
2047-01-10 Thu	45	—	unknown	18:50–19:20 (good, 0.5 h)	89.7° 17:45	11.33	98%	71.5°
2047-01-11 Fri	60	—	unknown	18:50–21:15 (good, 2.42 h)	89.6° 17:40	11.31	100%	83.3°
2047-01-12 Sat	76	—	unknown	18:55–22:35 (good, 3.67 h)	89.6° 17:40	11.29	99%	95.4°
2047-01-13 Sun	100	—	unknown	18:55–23:20 (good, 4.42 h)	89.8° 17:35	11.27	96%	107.6°
2047-01-14 Mon	100	—	unknown	18:55–23:25 (good, 4.5 h)	89.8° 17:30	11.25	90%	119.7°
2047-01-15 Tue	100	—	unknown	18:55–23:25 (good, 4.5 h)	89.7° 17:25	11.23	82%	131.3°
2047-01-16 Wed	100	—	unknown	18:55–23:25 (good, 4.5 h)	89.5° 17:20	11.21	72%	141.6°
2047-01-17 Thu	100	—	unknown	19:00–23:25 (good, 4.42 h)	89.7° 17:20	11.18	61%	149.2°
2047-01-18 Fri	100	—	unknown	19:00–23:25 (good, 4.42 h)	89.8° 17:15	11.16	50%	151.9°
2047-01-19 Sat	100	—	unknown	19:00–23:20 (good, 4.33 h)	89.8° 17:10	11.13	39%	148.4°
2047-01-20 Sun	100	—	unknown	19:00–23:15 (good, 4.25 h)	89.6° 17:05	11.11	28%	140.5°
2047-01-21 Mon	100	—	unknown	19:00–23:10 (good, 4.17 h)	89.5° 17:05	11.08	19%	130.3°
2047-01-22 Tue	100	—	unknown	19:05–23:10 (good, 4.08 h)	89.7° 17:00	11.06	11%	119.1°
2047-01-23 Wed	100	—	unknown	19:05–23:05 (good, 4.0 h)	89.8° 16:55	11.03	5%	107.4°
2047-01-24 Thu	100	—	unknown	19:05–23:00 (good, 3.92 h)	89.8° 16:50	11.0	1%	95.8°
2047-01-25 Fri	100	—	unknown	19:05–22:55 (good, 3.83 h)	89.6° 16:45	10.98	0%	84.2°
2047-01-26 Sat	98	—	unknown	19:10–22:50 (good, 3.67 h)	89.6° 16:45	10.95	1%	72.9°
2047-01-27 Sun	96	—	unknown	19:10–22:50 (good, 3.67 h)	89.8° 16:40	10.92	4%	62.1°
2047-01-28 Mon	90	—	unknown	19:10–22:45 (good, 3.58 h)	89.8° 16:35	10.89	8%	51.8°
2047-01-29 Tue	82	—	unknown	19:10–22:40 (good, 3.5 h)	89.7° 16:30	10.86	14%	42.6°
2047-01-30 Wed	71	—	unknown	19:10–22:35 (good, 3.42 h)	89.5° 16:25	10.82	22%	34.8°
2047-01-31 Thu	57	—	unknown	19:15–22:15 (good, 3.0 h)	89.7° 16:25	10.79	30%	29.6°
2047-02-01 Fri	46	—	unknown	19:15–22:00 (good, 2.75 h)	89.8° 16:20	10.76	39%	28.2°
2047-02-02 Sat	35	—	unknown	19:15–20:15 (good, 1.0 h)	89.8° 16:15	10.73	48%	31.2°
2047-02-03 Sun	28	—	unknown	19:15–22:45 (marginal, 3.5 h)	89.7° 16:10	10.69	58%	37.6°
2047-02-04 Mon	24	—	unknown	19:15–22:35 (marginal, 3.33 h)	89.5° 16:10	10.66	67%	46.2°
2047-02-05 Tue	22	—	unknown	19:20–22:25 (marginal, 3.08 h)	89.7° 16:05	10.62	76%	56.1°
2047-02-06 Wed	23	—	unknown	19:20–22:20 (marginal, 3.0 h)	89.8° 16:00	10.59	84%	66.9°
2047-02-07 Thu	27	—	unknown	18:50–22:20 (marginal, 3.5 h)	89.8° 15:55	10.55	91%	78.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-01-09&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.