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: 03-12 (6), 03-13 (5), 03-14 (4), 03-15 (3), 03-16 (2) — by astronomy; check the weather when the night is within four days.

2048-03-12astronomy score per night — click a bar for that night2048-04-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2048-03-21 Sat	0	—	unknown	—	89.6° 13:10	8.64	43%	61.8°
2048-03-22 Sun	0	—	unknown	—	89.7° 13:05	8.58	52%	72.0°
2048-03-23 Mon	0	—	unknown	—	89.8° 13:00	8.53	62%	82.5°
2048-03-24 Tue	0	—	unknown	—	89.7° 12:55	8.48	71%	93.3°
2048-03-25 Wed	0	—	unknown	—	89.6° 12:50	8.42	80%	104.4°
2048-03-26 Thu	0	—	unknown	—	89.6° 12:50	8.37	88%	115.7°
2048-03-27 Fri	0	—	unknown	—	89.8° 12:45	8.32	94%	126.8°
2048-03-28 Sat	0	—	unknown	—	89.8° 12:40	8.26	98%	137.3°
2048-03-29 Sun	0	—	unknown	—	89.7° 13:35	8.21	100%	146.1°
2048-03-30 Mon	0	—	unknown	—	89.5° 13:30	8.15	99%	150.9°
2048-03-31 Tue	0	—	unknown	—	89.7° 13:30	8.1	95%	149.5°
2048-04-01 Wed	0	—	unknown	—	89.8° 13:25	8.05	89%	142.4°
2048-04-02 Thu	0	—	unknown	—	89.8° 13:20	7.99	80%	132.2°
2048-04-03 Fri	0	—	unknown	—	89.6° 13:15	7.93	70%	120.7°
2048-04-04 Sat	0	—	unknown	—	89.6° 13:15	7.88	59%	108.6°
2048-04-05 Sun	0	—	unknown	—	89.7° 13:10	7.82	48%	96.5°
2048-04-06 Mon	0	—	unknown	—	89.8° 13:05	7.77	37%	84.5°
2048-04-07 Tue	0	—	unknown	—	89.8° 13:00	7.71	27%	72.8°
2048-04-08 Wed	0	—	unknown	—	89.6° 12:55	7.65	18%	61.5°
2048-04-09 Thu	0	—	unknown	—	89.6° 12:55	7.6	11%	50.9°
2048-04-10 Fri	0	—	unknown	—	89.8° 12:50	7.54	5%	41.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2048-03-12&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.