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: 12-07 (100), 12-08 (100), 12-09 (100), 12-10 (100), 12-11 (100) — by astronomy; check the weather when the night is within four days.

2045-12-07astronomy score per night — click a bar for that night2046-01-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-12-07 Thu	100	—	unknown	18:35–02:10 (good, 7.58 h)	89.7° 20:00	11.43	0%	131.9°
2045-12-08 Fri	100	—	unknown	18:35–02:05 (good, 7.5 h)	89.8° 19:55	11.44	0%	121.4°
2045-12-09 Sat	100	—	unknown	18:35–02:00 (good, 7.42 h)	89.8° 19:50	11.45	2%	110.6°
2045-12-10 Sun	100	—	unknown	18:35–01:55 (good, 7.33 h)	89.6° 19:45	11.46	6%	99.7°
2045-12-11 Mon	100	—	unknown	18:35–01:50 (good, 7.25 h)	89.6° 19:45	11.47	12%	88.9°
2045-12-12 Tue	100	—	unknown	18:35–01:50 (good, 7.25 h)	89.7° 19:40	11.47	18%	78.3°
2045-12-13 Wed	100	—	unknown	18:35–01:45 (good, 7.17 h)	89.8° 19:35	11.48	26%	67.9°
2045-12-14 Thu	97	—	unknown	18:35–01:40 (good, 7.08 h)	89.7° 19:30	11.49	35%	57.9°
2045-12-15 Fri	89	—	unknown	18:35–01:35 (good, 7.0 h)	89.6° 19:25	11.49	44%	48.4°
2045-12-16 Sat	82	—	unknown	18:35–01:30 (good, 6.92 h)	89.6° 19:25	11.5	54%	39.8°
2045-12-17 Sun	60	—	unknown	22:00–22:15 (good, 0.25 h)	89.8° 19:20	11.5	63%	32.8°
2045-12-18 Mon	44	—	unknown	18:35–01:50 (marginal, 7.25 h)	89.8° 19:15	11.5	72%	28.8°
2045-12-19 Tue	30	—	unknown	18:35–01:30 (marginal, 6.92 h)	89.7° 19:10	11.51	81%	29.4°
2045-12-20 Wed	26	—	unknown	18:35–01:05 (marginal, 6.5 h)	89.5° 19:10	11.51	88%	34.8°
2045-12-21 Thu	29	—	unknown	18:35–00:45 (marginal, 6.17 h)	89.7° 19:05	11.51	94%	43.4°
2045-12-22 Fri	38	—	unknown	18:35–00:45 (marginal, 6.17 h)	89.8° 19:00	11.51	98%	54.0°
2045-12-23 Sat	53	—	unknown	18:40–19:05 (good, 0.42 h)	89.8° 18:55	11.5	100%	65.8°
2045-12-24 Sun	73	—	unknown	18:40–21:55 (good, 3.25 h)	89.6° 18:50	11.5	99%	78.3°
2045-12-25 Mon	83	—	unknown	18:40–23:30 (good, 4.83 h)	89.6° 18:50	11.5	95%	91.2°
2045-12-26 Tue	100	—	unknown	18:40–00:30 (good, 5.83 h)	89.7° 18:45	11.49	89%	104.0°
2045-12-27 Wed	100	—	unknown	18:40–00:35 (good, 5.92 h)	89.8° 18:40	11.49	80%	116.6°
2045-12-28 Thu	100	—	unknown	18:40–00:35 (good, 5.92 h)	89.7° 18:35	11.48	70%	128.5°
2045-12-29 Fri	100	—	unknown	18:40–00:35 (good, 5.92 h)	89.6° 18:30	11.48	59%	139.2°
2045-12-30 Sat	100	—	unknown	18:40–00:35 (good, 5.92 h)	89.6° 18:30	11.47	48%	147.5°
2045-12-31 Sun	100	—	unknown	18:45–00:35 (good, 5.83 h)	89.8° 18:25	11.46	37%	151.5°
2046-01-01 Mon	100	—	unknown	18:45–00:30 (good, 5.75 h)	89.8° 18:20	11.45	27%	149.9°
2046-01-02 Tue	100	—	unknown	18:45–00:25 (good, 5.67 h)	89.7° 18:15	11.44	18%	143.6°
2046-01-03 Wed	100	—	unknown	18:45–00:20 (good, 5.58 h)	89.5° 18:15	11.43	11%	134.7°
2046-01-04 Thu	100	—	unknown	18:45–00:20 (good, 5.58 h)	89.7° 18:10	11.41	5%	124.5°
2046-01-05 Fri	100	—	unknown	18:45–00:15 (good, 5.5 h)	89.8° 18:05	11.4	2%	113.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-12-07&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.