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: 01-31 (66), 02-12 (56), 02-13 (56), 02-01 (53), 02-14 (53) — by astronomy; check the weather when the night is within four days.

2028-01-31astronomy score per night — click a bar for that night2028-02-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-01-31 Mon	66	—	unknown	19:15–22:35 (good, 3.33 h)	89.7° 16:25	10.81	23%	33.4°
2028-02-01 Tue	53	—	unknown	19:15–22:10 (good, 2.92 h)	89.7° 16:20	10.77	32%	28.8°
2028-02-02 Wed	42	—	unknown	19:15–21:55 (good, 2.67 h)	89.7° 16:15	10.74	41%	28.6°
2028-02-03 Thu	32	—	unknown	19:15–19:25 (good, 0.17 h)	89.5° 16:10	10.71	51%	33.0°
2028-02-04 Fri	26	—	unknown	19:15–22:35 (marginal, 3.33 h)	89.6° 16:10	10.67	62%	40.9°
2028-02-05 Sat	22	—	unknown	19:20–22:25 (marginal, 3.08 h)	89.7° 16:05	10.64	72%	51.1°
2028-02-06 Sun	22	—	unknown	19:20–22:20 (marginal, 3.0 h)	89.7° 16:00	10.6	81%	62.6°
2028-02-07 Mon	25	—	unknown	19:20–22:20 (marginal, 3.0 h)	89.6° 15:55	10.57	90%	75.0°
2028-02-08 Tue	31	—	unknown	19:20–20:05 (good, 0.75 h)	89.5° 15:50	10.53	96%	88.0°
2028-02-09 Wed	38	—	unknown	19:25–21:20 (good, 1.92 h)	89.6° 15:50	10.49	99%	101.4°
2028-02-10 Thu	46	—	unknown	19:25–21:35 (good, 2.17 h)	89.7° 15:45	10.46	100%	114.6°
2028-02-11 Fri	50	—	unknown	19:25–21:35 (good, 2.17 h)	89.7° 15:40	10.42	97%	127.4°
2028-02-12 Sat	56	—	unknown	19:25–21:35 (good, 2.17 h)	89.6° 15:35	10.38	92%	138.8°
2028-02-13 Sun	56	—	unknown	19:25–21:40 (good, 2.25 h)	89.5° 15:35	10.34	84%	147.6°
2028-02-14 Mon	53	—	unknown	19:30–21:40 (good, 2.17 h)	89.7° 15:30	10.3	75%	151.8°
2028-02-15 Tue	51	—	unknown	19:30–21:35 (good, 2.08 h)	89.7° 15:25	10.27	65%	149.8°
2028-02-16 Wed	50	—	unknown	19:30–21:30 (good, 2.0 h)	89.7° 15:20	10.23	54%	143.2°
2028-02-17 Thu	48	—	unknown	19:30–21:25 (good, 1.92 h)	89.5° 15:15	10.18	44%	134.2°
2028-02-18 Fri	45	—	unknown	19:35–21:20 (good, 1.75 h)	89.6° 15:15	10.14	34%	124.2°
2028-02-19 Sat	43	—	unknown	19:35–21:20 (good, 1.75 h)	89.7° 15:10	10.1	25%	113.8°
2028-02-20 Sun	41	—	unknown	19:35–21:15 (good, 1.67 h)	89.7° 15:05	10.06	17%	103.3°
2028-02-21 Mon	40	—	unknown	19:35–21:10 (good, 1.58 h)	89.6° 15:00	10.02	10%	92.8°
2028-02-22 Tue	38	—	unknown	19:35–21:05 (good, 1.5 h)	89.5° 14:55	9.98	6%	82.3°
2028-02-23 Wed	35	—	unknown	19:40–21:00 (good, 1.33 h)	89.6° 14:55	9.93	2%	71.9°
2028-02-24 Thu	33	—	unknown	19:40–21:00 (good, 1.33 h)	89.7° 14:50	9.89	0%	61.8°
2028-02-25 Fri	32	—	unknown	19:40–20:55 (good, 1.25 h)	89.7° 14:45	9.85	0%	52.0°
2028-02-26 Sat	31	—	unknown	19:40–20:50 (good, 1.17 h)	89.6° 14:40	9.8	2%	42.9°
2028-02-27 Sun	27	—	unknown	19:45–20:45 (good, 1.0 h)	89.5° 14:40	9.76	6%	35.1°
2028-02-28 Mon	24	—	unknown	19:45–20:40 (good, 0.92 h)	89.7° 14:35	9.71	11%	29.7°
2028-02-29 Tue	20	—	unknown	19:45–20:30 (good, 0.75 h)	89.7° 14:30	9.67	18%	28.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-01-31&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.