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: 01-17 (100), 01-18 (94), 01-19 (89), 02-02 (79), 02-03 (79) — by astronomy; check the weather when the night is within four days.

2048-01-17astronomy score per night — click a bar for that night2048-02-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2048-01-17 Fri	100	—	unknown	19:00–23:30 (good, 4.5 h)	89.8° 17:20	11.19	8%	61.5°
2048-01-18 Sat	94	—	unknown	19:00–23:25 (good, 4.42 h)	89.8° 17:15	11.16	14%	50.6°
2048-01-19 Sun	89	—	unknown	19:00–23:20 (good, 4.33 h)	89.7° 17:10	11.14	22%	41.0°
2048-01-20 Mon	76	—	unknown	19:00–23:15 (good, 4.25 h)	89.5° 17:10	11.12	31%	33.4°
2048-01-21 Tue	59	—	unknown	19:00–22:50 (good, 3.83 h)	89.7° 17:05	11.09	41%	29.0°
2048-01-22 Wed	45	—	unknown	19:05–21:00 (good, 1.92 h)	89.8° 17:00	11.06	50%	29.0°
2048-01-23 Thu	35	—	unknown	19:05–23:30 (marginal, 4.42 h)	89.8° 16:55	11.04	60%	33.2°
2048-01-24 Fri	28	—	unknown	19:05–23:15 (marginal, 4.17 h)	89.6° 16:50	11.01	69%	40.2°
2048-01-25 Sat	26	—	unknown	19:05–23:05 (marginal, 4.0 h)	89.6° 16:50	10.98	77%	48.9°
2048-01-26 Sun	27	—	unknown	19:05–23:00 (marginal, 3.92 h)	89.8° 16:45	10.95	84%	58.5°
2048-01-27 Mon	30	—	unknown	19:10–22:55 (marginal, 3.75 h)	89.8° 16:40	10.92	91%	68.7°
2048-01-28 Tue	37	—	unknown	19:10–19:55 (good, 0.75 h)	89.7° 16:35	10.89	96%	79.4°
2048-01-29 Wed	46	—	unknown	19:10–20:55 (good, 1.75 h)	89.5° 16:30	10.86	99%	90.4°
2048-01-30 Thu	56	—	unknown	19:10–22:00 (good, 2.83 h)	89.7° 16:30	10.83	100%	101.6°
2048-01-31 Fri	65	—	unknown	19:15–22:15 (good, 3.0 h)	89.8° 16:25	10.8	99%	112.9°
2048-02-01 Sat	78	—	unknown	19:15–22:15 (good, 3.0 h)	89.8° 16:20	10.77	96%	124.0°
2048-02-02 Sun	79	—	unknown	19:15–22:15 (good, 3.0 h)	89.7° 16:15	10.74	90%	134.6°
2048-02-03 Mon	79	—	unknown	19:15–22:15 (good, 3.0 h)	89.5° 16:15	10.7	83%	143.8°
2048-02-04 Tue	78	—	unknown	19:15–22:20 (good, 3.08 h)	89.7° 16:10	10.67	74%	150.0°
2048-02-05 Wed	74	—	unknown	19:20–22:15 (good, 2.92 h)	89.8° 16:05	10.63	63%	151.2°
2048-02-06 Thu	73	—	unknown	19:20–22:10 (good, 2.83 h)	89.8° 16:00	10.6	52%	146.5°
2048-02-07 Fri	70	—	unknown	19:20–22:05 (good, 2.75 h)	89.6° 15:55	10.56	41%	137.8°
2048-02-08 Sat	68	—	unknown	19:20–22:00 (good, 2.67 h)	89.6° 15:55	10.53	30%	127.0°
2048-02-09 Sun	64	—	unknown	19:25–22:00 (good, 2.58 h)	89.8° 15:50	10.49	20%	115.2°
2048-02-10 Mon	62	—	unknown	19:25–21:55 (good, 2.5 h)	89.8° 15:45	10.45	12%	103.0°
2048-02-11 Tue	60	—	unknown	19:25–21:50 (good, 2.42 h)	89.7° 15:40	10.41	5%	90.5°
2048-02-12 Wed	59	—	unknown	19:25–21:45 (good, 2.33 h)	89.5° 15:35	10.38	2%	78.2°
2048-02-13 Thu	57	—	unknown	19:25–21:40 (good, 2.25 h)	89.6° 15:35	10.34	0%	66.3°
2048-02-14 Fri	53	—	unknown	19:30–21:40 (good, 2.17 h)	89.8° 15:30	10.3	1%	55.0°
2048-02-15 Sat	51	—	unknown	19:30–21:35 (good, 2.08 h)	89.8° 15:25	10.26	4%	44.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2048-01-17&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.