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: 01-14 (100), 01-15 (100), 01-16 (100), 01-17 (100), 01-18 (100) — by astronomy; check the weather when the night is within four days.

2045-01-14astronomy score per night — click a bar for that night2045-02-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-01-14 Sat	100	—	unknown	18:55–23:35 (good, 4.67 h)	89.6° 17:30	11.24	9%	124.0°
2045-01-15 Sun	100	—	unknown	18:55–23:35 (good, 4.67 h)	89.8° 17:25	11.22	5%	114.1°
2045-01-16 Mon	100	—	unknown	19:00–23:30 (good, 4.5 h)	89.8° 17:20	11.19	2%	103.9°
2045-01-17 Tue	100	—	unknown	19:00–23:25 (good, 4.42 h)	89.7° 17:15	11.17	0%	93.6°
2045-01-18 Wed	100	—	unknown	19:00–23:20 (good, 4.33 h)	89.5° 17:15	11.15	0%	83.3°
2045-01-19 Thu	100	—	unknown	19:00–23:20 (good, 4.33 h)	89.7° 17:10	11.12	3%	73.0°
2045-01-20 Fri	100	—	unknown	19:00–23:15 (good, 4.25 h)	89.8° 17:05	11.1	7%	62.8°
2045-01-21 Sat	96	—	unknown	19:05–23:10 (good, 4.08 h)	89.8° 17:00	11.07	12%	53.0°
2045-01-22 Sun	90	—	unknown	19:05–23:05 (good, 4.0 h)	89.6° 16:55	11.05	19%	43.7°
2045-01-23 Mon	76	—	unknown	19:05–23:00 (good, 3.92 h)	89.6° 16:55	11.02	27%	35.8°
2045-01-24 Tue	59	—	unknown	19:05–22:35 (good, 3.5 h)	89.7° 16:50	10.99	37%	30.3°
2045-01-25 Wed	45	—	unknown	19:05–21:30 (good, 2.42 h)	89.8° 16:45	10.96	47%	29.2°
2045-01-26 Thu	33	—	unknown	19:10–23:15 (marginal, 4.08 h)	89.7° 16:40	10.93	58%	33.1°
2045-01-27 Fri	26	—	unknown	19:10–23:00 (marginal, 3.83 h)	89.6° 16:35	10.9	68%	41.1°
2045-01-28 Sat	24	—	unknown	19:10–22:45 (marginal, 3.58 h)	89.6° 16:35	10.87	78%	51.5°
2045-01-29 Sun	26	—	unknown	19:10–22:45 (marginal, 3.58 h)	89.8° 16:30	10.84	87%	63.5°
2045-01-30 Mon	32	—	unknown	19:10–19:25 (good, 0.25 h)	89.8° 16:25	10.81	94%	76.3°
2045-01-31 Tue	41	—	unknown	19:15–20:40 (good, 1.42 h)	89.7° 16:20	10.78	99%	89.5°
2045-02-01 Wed	52	—	unknown	19:15–21:55 (good, 2.67 h)	89.5° 16:15	10.74	100%	102.8°
2045-02-02 Thu	63	—	unknown	19:15–22:05 (good, 2.83 h)	89.7° 16:15	10.71	98%	115.8°
2045-02-03 Fri	73	—	unknown	19:15–22:05 (good, 2.83 h)	89.8° 16:10	10.68	94%	128.1°
2045-02-04 Sat	73	—	unknown	19:20–22:05 (good, 2.75 h)	89.8° 16:05	10.64	87%	138.8°
2045-02-05 Sun	73	—	unknown	19:20–22:10 (good, 2.83 h)	89.6° 16:00	10.61	78%	147.0°
2045-02-06 Mon	70	—	unknown	19:20–22:05 (good, 2.75 h)	89.6° 16:00	10.57	69%	150.9°
2045-02-07 Tue	68	—	unknown	19:20–22:05 (good, 2.75 h)	89.7° 15:55	10.54	59%	149.5°
2045-02-08 Wed	66	—	unknown	19:20–22:00 (good, 2.67 h)	89.8° 15:50	10.5	48%	143.8°
2045-02-09 Thu	63	—	unknown	19:25–21:55 (good, 2.5 h)	89.7° 15:45	10.46	39%	135.7°
2045-02-10 Fri	61	—	unknown	19:25–21:50 (good, 2.42 h)	89.6° 15:40	10.42	30%	126.5°
2045-02-11 Sat	59	—	unknown	19:25–21:45 (good, 2.33 h)	89.6° 15:40	10.39	21%	116.7°
2045-02-12 Sun	57	—	unknown	19:25–21:45 (good, 2.33 h)	89.8° 15:35	10.35	14%	106.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-01-14&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.