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 (98) — by astronomy; check the weather when the night is within four days.

2029-01-13astronomy score per night — click a bar for that night2029-02-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-01-13 Sat	100	—	unknown	18:55–23:40 (good, 4.75 h)	89.6° 17:30	11.26	1%	101.0°
2029-01-14 Sun	100	—	unknown	18:55–23:35 (good, 4.67 h)	89.5° 17:30	11.24	0%	89.6°
2029-01-15 Mon	100	—	unknown	18:55–23:35 (good, 4.67 h)	89.7° 17:25	11.22	2%	78.4°
2029-01-16 Tue	100	—	unknown	18:55–23:30 (good, 4.58 h)	89.7° 17:20	11.2	5%	67.6°
2029-01-17 Wed	98	—	unknown	19:00–23:25 (good, 4.42 h)	89.7° 17:15	11.17	10%	57.2°
2029-01-18 Thu	93	—	unknown	19:00–23:20 (good, 4.33 h)	89.5° 17:10	11.15	17%	47.6°
2029-01-19 Fri	87	—	unknown	19:00–23:15 (good, 4.25 h)	89.6° 17:10	11.13	24%	39.0°
2029-01-20 Sat	72	—	unknown	19:00–23:00 (good, 4.0 h)	89.7° 17:05	11.1	33%	32.3°
2029-01-21 Sun	56	—	unknown	19:05–22:45 (good, 3.67 h)	89.7° 17:00	11.08	42%	28.6°
2029-01-22 Mon	43	—	unknown	19:05–20:30 (good, 1.42 h)	89.6° 16:55	11.05	51%	29.1°
2029-01-23 Tue	33	—	unknown	19:05–23:25 (marginal, 4.33 h)	89.5° 16:50	11.02	61%	33.9°
2029-01-24 Wed	27	—	unknown	19:05–23:10 (marginal, 4.08 h)	89.6° 16:50	10.99	70%	41.5°
2029-01-25 Thu	26	—	unknown	19:05–23:00 (marginal, 3.92 h)	89.7° 16:45	10.96	79%	51.1°
2029-01-26 Fri	27	—	unknown	19:10–22:55 (marginal, 3.75 h)	89.7° 16:40	10.94	87%	61.8°
2029-01-27 Sat	33	—	unknown	19:10–19:15 (good, 0.08 h)	89.6° 16:35	10.91	93%	73.3°
2029-01-28 Sun	42	—	unknown	19:10–20:25 (good, 1.25 h)	89.5° 16:35	10.88	98%	85.5°
2029-01-29 Mon	52	—	unknown	19:10–21:40 (good, 2.5 h)	89.7° 16:30	10.84	100%	98.0°
2029-01-30 Tue	64	—	unknown	19:10–22:10 (good, 3.0 h)	89.7° 16:25	10.81	99%	110.7°
2029-01-31 Wed	78	—	unknown	19:15–22:15 (good, 3.0 h)	89.7° 16:20	10.78	96%	123.1°
2029-02-01 Thu	79	—	unknown	19:15–22:15 (good, 3.0 h)	89.5° 16:15	10.75	90%	134.7°
2029-02-02 Fri	79	—	unknown	19:15–22:15 (good, 3.0 h)	89.6° 16:15	10.71	82%	144.6°
2029-02-03 Sat	78	—	unknown	19:15–22:20 (good, 3.08 h)	89.7° 16:10	10.68	72%	150.8°
2029-02-04 Sun	74	—	unknown	19:20–22:15 (good, 2.92 h)	89.7° 16:05	10.65	61%	151.0°
2029-02-05 Mon	73	—	unknown	19:20–22:10 (good, 2.83 h)	89.6° 16:00	10.61	50%	145.5°
2029-02-06 Tue	70	—	unknown	19:20–22:05 (good, 2.75 h)	89.5° 15:55	10.58	39%	136.7°
2029-02-07 Wed	68	—	unknown	19:20–22:00 (good, 2.67 h)	89.6° 15:55	10.54	28%	126.3°
2029-02-08 Thu	66	—	unknown	19:20–22:00 (good, 2.67 h)	89.7° 15:50	10.5	19%	115.3°
2029-02-09 Fri	62	—	unknown	19:25–21:55 (good, 2.5 h)	89.7° 15:45	10.47	12%	104.0°
2029-02-10 Sat	61	—	unknown	19:25–21:50 (good, 2.42 h)	89.6° 15:40	10.43	6%	92.8°
2029-02-11 Sun	59	—	unknown	19:25–21:45 (good, 2.33 h)	89.5° 15:40	10.39	2%	81.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-01-13&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.