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: 02-10 (61), 02-11 (59), 02-12 (57), 02-13 (54), 02-14 (52) — by astronomy; check the weather when the night is within four days.

2045-02-10astronomy score per night — click a bar for that night2045-03-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2045-02-13 Mon	54	—	unknown	19:30–21:40 (good, 2.17 h)	89.8° 15:30	10.31	8%	96.3°
2045-02-14 Tue	52	—	unknown	19:30–21:35 (good, 2.08 h)	89.7° 15:25	10.27	4%	86.0°
2045-02-15 Wed	50	—	unknown	19:30–21:30 (good, 2.0 h)	89.5° 15:20	10.23	1%	75.6°
2045-02-16 Thu	48	—	unknown	19:30–21:25 (good, 1.92 h)	89.7° 15:20	10.19	0%	65.3°
2045-02-17 Fri	45	—	unknown	19:35–21:25 (good, 1.83 h)	89.8° 15:15	10.15	1%	55.3°
2045-02-18 Sat	44	—	unknown	19:35–21:20 (good, 1.75 h)	89.8° 15:10	10.11	4%	45.8°
2045-02-19 Sun	40	—	unknown	19:35–21:15 (good, 1.67 h)	89.6° 15:05	10.07	8%	37.4°
2045-02-20 Mon	35	—	unknown	19:35–21:05 (good, 1.5 h)	89.5° 15:05	10.02	14%	31.2°
2045-02-21 Tue	29	—	unknown	19:35–20:55 (good, 1.33 h)	89.7° 15:00	9.98	22%	28.9°
2045-02-22 Wed	23	—	unknown	19:40–20:40 (good, 1.0 h)	89.8° 14:55	9.94	32%	31.6°
2045-02-23 Thu	18	—	unknown	19:40–20:00 (good, 0.33 h)	89.7° 14:50	9.9	42%	38.5°
2045-02-24 Fri	15	—	unknown	19:40–21:25 (marginal, 1.75 h)	89.6° 14:45	9.85	53%	48.1°
2045-02-25 Sat	12	—	unknown	19:40–21:15 (marginal, 1.58 h)	89.6° 14:45	9.81	64%	59.2°
2045-02-26 Sun	11	—	unknown	19:45–21:10 (marginal, 1.42 h)	89.8° 14:40	9.76	74%	71.3°
2045-02-27 Mon	12	—	unknown	19:45–21:10 (marginal, 1.42 h)	89.8° 14:35	9.72	84%	83.9°
2045-02-28 Tue	14	—	unknown	19:45–19:50 (good, 0.08 h)	89.7° 14:30	9.67	92%	96.9°
2045-03-01 Wed	16	—	unknown	19:45–20:15 (good, 0.5 h)	89.5° 14:25	9.63	97%	109.9°
2045-03-02 Thu	17	—	unknown	19:50–20:20 (good, 0.5 h)	89.7° 14:25	9.58	100%	122.5°
2045-03-03 Fri	17	—	unknown	19:50–20:20 (good, 0.5 h)	89.8° 14:20	9.54	99%	134.1°
2045-03-04 Sat	19	—	unknown	19:50–20:15 (good, 0.42 h)	89.8° 14:15	9.49	96%	143.8°
2045-03-05 Sun	18	—	unknown	19:50–20:20 (good, 0.5 h)	89.6° 14:10	9.44	91%	149.9°
2045-03-06 Mon	16	—	unknown	19:50–20:15 (good, 0.42 h)	89.5° 14:10	9.4	84%	150.7°
2045-03-07 Tue	13	—	unknown	19:55–20:15 (good, 0.33 h)	89.7° 14:05	9.35	75%	146.3°
2045-03-08 Wed	12	—	unknown	19:55–20:10 (good, 0.25 h)	89.8° 14:00	9.3	66%	138.6°
2045-03-09 Thu	11	—	unknown	19:55–20:05 (good, 0.17 h)	89.8° 13:55	9.25	56%	129.5°
2045-03-10 Fri	9	—	unknown	19:55–20:00 (good, 0.08 h)	89.6° 13:50	9.2	46%	119.7°
2045-03-11 Sat	7	—	unknown	20:00–20:30 (marginal, 0.5 h)	89.6° 13:50	9.16	37%	109.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-02-10&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.