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: 01-27 (96), 01-28 (90), 01-29 (82), 01-30 (71), 01-31 (57) — by astronomy; check the weather when the night is within four days.

2047-01-27astronomy score per night — click a bar for that night2047-02-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2047-02-08 Fri	33	—	unknown	19:20–20:20 (good, 1.0 h)	89.6° 15:50	10.52	96%	90.5°
2047-02-09 Sat	39	—	unknown	19:25–21:25 (good, 2.0 h)	89.6° 15:50	10.48	99%	102.8°
2047-02-10 Sun	47	—	unknown	19:25–21:35 (good, 2.17 h)	89.8° 15:45	10.44	100%	115.3°
2047-02-11 Mon	50	—	unknown	19:25–21:35 (good, 2.17 h)	89.8° 15:40	10.41	98%	127.4°
2047-02-12 Tue	56	—	unknown	19:25–21:35 (good, 2.17 h)	89.7° 15:35	10.37	92%	138.5°
2047-02-13 Wed	54	—	unknown	19:30–21:40 (good, 2.17 h)	89.5° 15:30	10.33	85%	147.4°
2047-02-14 Thu	53	—	unknown	19:30–21:35 (good, 2.08 h)	89.7° 15:30	10.29	76%	151.7°
2047-02-15 Fri	51	—	unknown	19:30–21:35 (good, 2.08 h)	89.8° 15:25	10.25	65%	149.7°
2047-02-16 Sat	50	—	unknown	19:30–21:30 (good, 2.0 h)	89.8° 15:20	10.21	54%	142.4°
2047-02-17 Sun	48	—	unknown	19:30–21:25 (good, 1.92 h)	89.7° 15:15	10.17	43%	132.6°
2047-02-18 Mon	45	—	unknown	19:35–21:20 (good, 1.75 h)	89.5° 15:15	10.13	32%	121.7°
2047-02-19 Tue	43	—	unknown	19:35–21:20 (good, 1.75 h)	89.7° 15:10	10.09	22%	110.3°
2047-02-20 Wed	41	—	unknown	19:35–21:15 (good, 1.67 h)	89.8° 15:05	10.04	14%	98.8°
2047-02-21 Thu	40	—	unknown	19:35–21:10 (good, 1.58 h)	89.8° 15:00	10.0	8%	87.4°
2047-02-22 Fri	37	—	unknown	19:40–21:05 (good, 1.42 h)	89.6° 14:55	9.96	3%	76.2°
2047-02-23 Sat	35	—	unknown	19:40–21:00 (good, 1.33 h)	89.6° 14:55	9.92	1%	65.4°
2047-02-24 Sun	33	—	unknown	19:40–21:00 (good, 1.33 h)	89.8° 14:50	9.87	0%	55.0°
2047-02-25 Mon	32	—	unknown	19:40–20:55 (good, 1.25 h)	89.8° 14:45	9.83	1%	45.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-01-27&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.