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: 12-31 (100), 01-01 (100), 01-02 (100), 01-03 (100), 01-16 (100) — by astronomy; check the weather when the night is within four days.

2043-12-31astronomy score per night — click a bar for that night2044-01-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-12-31 Thu	100	—	unknown	18:45–00:35 (good, 5.83 h)	89.7° 18:25	11.46	0%	102.5°
2044-01-01 Fri	100	—	unknown	18:45–00:30 (good, 5.75 h)	89.5° 18:20	11.45	2%	92.1°
2044-01-02 Sat	100	—	unknown	18:45–00:25 (good, 5.67 h)	89.6° 18:20	11.44	6%	81.6°
2044-01-03 Sun	100	—	unknown	18:45–00:25 (good, 5.67 h)	89.8° 18:15	11.43	11%	71.0°
2044-01-04 Mon	98	—	unknown	18:45–00:20 (good, 5.58 h)	89.8° 18:10	11.42	18%	60.5°
2044-01-05 Tue	90	—	unknown	18:45–00:15 (good, 5.5 h)	89.7° 18:05	11.41	27%	50.4°
2044-01-06 Wed	82	—	unknown	18:45–00:10 (good, 5.42 h)	89.5° 18:05	11.39	37%	41.2°
2044-01-07 Thu	70	—	unknown	18:50–23:45 (good, 4.92 h)	89.7° 18:00	11.38	47%	33.9°
2044-01-08 Fri	49	—	unknown	18:50–00:35 (marginal, 5.75 h)	89.8° 17:55	11.36	58%	30.4°
2044-01-09 Sat	34	—	unknown	18:50–00:15 (marginal, 5.42 h)	89.8° 17:50	11.35	69%	32.3°
2044-01-10 Sun	27	—	unknown	18:50–23:55 (marginal, 5.08 h)	89.6° 17:45	11.33	80%	39.3°
2044-01-11 Mon	27	—	unknown	18:50–23:45 (marginal, 4.92 h)	89.6° 17:45	11.31	88%	49.4°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-12-31&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.