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: 02-20 (22), 03-02 (22), 02-28 (21), 02-29 (21), 03-01 (21) — by astronomy; check the weather when the night is within four days.

2048-02-20astronomy score per night — click a bar for that night2048-03-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2048-02-20 Thu	22	—	unknown	19:35–20:20 (good, 0.75 h)	89.8° 15:05	10.05	42%	37.8°
2048-02-21 Fri	18	—	unknown	19:35–21:40 (marginal, 2.08 h)	89.6° 15:00	10.01	51%	45.9°
2048-02-22 Sat	15	—	unknown	19:40–21:30 (marginal, 1.83 h)	89.6° 15:00	9.97	61%	55.2°
2048-02-23 Sun	14	—	unknown	19:40–21:25 (marginal, 1.75 h)	89.8° 14:55	9.93	70%	65.2°
2048-02-24 Mon	14	—	unknown	19:40–21:20 (marginal, 1.67 h)	89.8° 14:50	9.88	78%	75.6°
2048-02-25 Tue	15	—	unknown	19:40–21:20 (marginal, 1.67 h)	89.7° 14:45	9.84	86%	86.4°
2048-02-26 Wed	17	—	unknown	19:40–20:05 (good, 0.42 h)	89.6° 14:40	9.8	92%	97.6°
2048-02-27 Thu	19	—	unknown	19:45–20:25 (good, 0.67 h)	89.6° 14:40	9.75	97%	108.9°
2048-02-28 Fri	21	—	unknown	19:45–20:30 (good, 0.75 h)	89.8° 14:35	9.71	99%	120.2°
2048-02-29 Sat	21	—	unknown	19:45–20:30 (good, 0.75 h)	89.8° 14:30	9.66	100%	131.2°
2048-03-01 Sun	21	—	unknown	19:45–20:25 (good, 0.67 h)	89.7° 14:25	9.62	98%	141.1°
2048-03-02 Mon	22	—	unknown	19:50–20:30 (good, 0.67 h)	89.5° 14:25	9.57	93%	148.6°
2048-03-03 Tue	21	—	unknown	19:50–20:30 (good, 0.67 h)	89.7° 14:20	9.52	86%	151.3°
2048-03-04 Wed	19	—	unknown	19:50–20:25 (good, 0.58 h)	89.8° 14:15	9.48	77%	147.8°
2048-03-05 Thu	18	—	unknown	19:50–20:20 (good, 0.5 h)	89.8° 14:10	9.43	67%	139.8°
2048-03-06 Fri	14	—	unknown	19:55–20:15 (good, 0.33 h)	89.6° 14:05	9.38	56%	129.4°
2048-03-07 Sat	13	—	unknown	19:55–20:10 (good, 0.25 h)	89.6° 14:05	9.34	44%	117.9°
2048-03-08 Sun	11	—	unknown	19:55–20:10 (good, 0.25 h)	89.7° 14:00	9.29	34%	106.0°
2048-03-09 Mon	10	—	unknown	19:55–20:05 (good, 0.17 h)	89.8° 13:55	9.24	23%	93.9°
2048-03-10 Tue	8	—	unknown	19:25–20:35 (marginal, 1.17 h)	89.7° 13:50	9.19	15%	81.8°
2048-03-11 Wed	7	—	unknown	20:00–20:30 (marginal, 0.5 h)	89.6° 13:45	9.14	8%	70.1°
2048-03-12 Thu	6	—	unknown	20:00–20:25 (marginal, 0.42 h)	89.6° 13:45	9.09	3%	58.8°
2048-03-13 Fri	5	—	unknown	20:00–20:20 (marginal, 0.33 h)	89.8° 13:40	9.04	1%	48.2°
2048-03-14 Sat	4	—	unknown	20:00–20:20 (marginal, 0.33 h)	89.8° 13:35	8.99	0%	39.1°
2048-03-15 Sun	3	—	unknown	20:05–20:15 (marginal, 0.17 h)	89.7° 13:30	8.94	2%	32.1°
2048-03-16 Mon	2	—	unknown	20:05–20:10 (marginal, 0.08 h)	89.5° 13:30	8.89	6%	28.9°
2048-03-17 Tue	1	—	unknown	—	89.7° 13:25	8.84	11%	30.3°
2048-03-18 Wed	1	—	unknown	—	89.8° 13:20	8.79	18%	35.5°
2048-03-19 Thu	1	—	unknown	—	89.8° 13:15	8.74	25%	43.2°
2048-03-20 Fri	0	—	unknown	—	89.6° 13:10	8.69	34%	52.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2048-02-20&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.