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: 01-16 (100), 01-17 (100), 01-18 (100), 01-19 (100), 01-20 (100) — by astronomy; check the weather when the night is within four days.

2044-01-12astronomy score per night — click a bar for that night2044-02-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-01-12 Tue	33	—	unknown	18:55–23:40 (marginal, 4.75 h)	89.7° 17:40	11.29	95%	61.2°
2044-01-13 Wed	44	—	unknown	18:55–19:40 (good, 0.75 h)	89.8° 17:35	11.27	99%	73.7°
2044-01-14 Thu	61	—	unknown	18:55–21:25 (good, 2.5 h)	89.7° 17:30	11.25	100%	86.6°
2044-01-15 Fri	79	—	unknown	18:55–22:50 (good, 3.92 h)	89.5° 17:25	11.23	98%	99.3°
2044-01-16 Sat	100	—	unknown	18:55–23:15 (good, 4.33 h)	89.6° 17:25	11.21	94%	111.6°
2044-01-17 Sun	100	—	unknown	19:00–23:15 (good, 4.25 h)	89.8° 17:20	11.19	87%	123.1°
2044-01-18 Mon	100	—	unknown	19:00–23:15 (good, 4.25 h)	89.8° 17:15	11.17	79%	133.4°
2044-01-19 Tue	100	—	unknown	19:00–23:15 (good, 4.25 h)	89.7° 17:10	11.14	70%	142.0°
2044-01-20 Wed	100	—	unknown	19:00–23:15 (good, 4.25 h)	89.5° 17:10	11.12	60%	147.8°
2044-01-21 Thu	100	—	unknown	19:00–23:15 (good, 4.25 h)	89.7° 17:05	11.09	50%	149.8°
2044-01-22 Fri	100	—	unknown	19:05–23:10 (good, 4.08 h)	89.8° 17:00	11.07	41%	147.4°
2044-01-23 Sat	100	—	unknown	19:05–23:05 (good, 4.0 h)	89.8° 16:55	11.04	32%	141.7°
2044-01-24 Sun	100	—	unknown	19:05–23:00 (good, 3.92 h)	89.6° 16:50	11.01	24%	134.0°
2044-01-25 Mon	100	—	unknown	19:05–22:55 (good, 3.83 h)	89.6° 16:50	10.98	16%	125.1°
2044-01-26 Tue	99	—	unknown	19:05–22:55 (good, 3.83 h)	89.7° 16:45	10.95	10%	115.5°
2044-01-27 Wed	96	—	unknown	19:10–22:50 (good, 3.67 h)	89.8° 16:40	10.93	5%	105.4°
2044-01-28 Thu	95	—	unknown	19:10–22:45 (good, 3.58 h)	89.7° 16:35	10.9	2%	95.0°
2044-01-29 Fri	92	—	unknown	19:10–22:40 (good, 3.5 h)	89.5° 16:30	10.86	0%	84.3°
2044-01-30 Sat	90	—	unknown	19:10–22:35 (good, 3.42 h)	89.6° 16:30	10.83	1%	73.6°
2044-01-31 Sun	86	—	unknown	19:15–22:35 (good, 3.33 h)	89.8° 16:25	10.8	3%	62.9°
2044-02-01 Mon	82	—	unknown	19:15–22:30 (good, 3.25 h)	89.8° 16:20	10.77	8%	52.5°
2044-02-02 Tue	74	—	unknown	19:15–22:25 (good, 3.17 h)	89.7° 16:15	10.74	14%	43.0°
2044-02-03 Wed	62	—	unknown	19:15–22:10 (good, 2.92 h)	89.5° 16:15	10.7	22%	35.1°
2044-02-04 Thu	49	—	unknown	19:15–22:00 (good, 2.75 h)	89.7° 16:10	10.67	32%	30.6°
2044-02-05 Fri	37	—	unknown	19:20–21:25 (good, 2.08 h)	89.8° 16:05	10.63	43%	31.1°
2044-02-06 Sat	28	—	unknown	19:20–22:35 (marginal, 3.25 h)	89.8° 16:00	10.6	54%	36.8°
2044-02-07 Sun	22	—	unknown	19:20–22:25 (marginal, 3.08 h)	89.6° 15:55	10.56	65%	45.9°
2044-02-08 Mon	20	—	unknown	19:20–22:15 (marginal, 2.92 h)	89.6° 15:55	10.53	76%	56.9°
2044-02-09 Tue	21	—	unknown	19:25–22:10 (marginal, 2.75 h)	89.7° 15:50	10.49	85%	68.9°
2044-02-10 Wed	25	—	unknown	18:50–22:10 (marginal, 3.33 h)	89.8° 15:45	10.45	92%	81.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-01-12&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.