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: 08-09 (100), 08-10 (100), 08-11 (100), 08-12 (100), 08-13 (100) — by astronomy; check the weather when the night is within four days.

2046-08-09astronomy score per night — click a bar for that night2046-09-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-08-09 Thu	100	—	unknown	22:55–04:40 (good, 5.75 h)	89.7° 04:50	6.31	60%	139.5°
2046-08-10 Fri	100	—	unknown	22:50–04:40 (good, 5.83 h)	89.5° 04:50	6.36	70%	129.5°
2046-08-11 Sat	100	—	unknown	22:50–04:40 (good, 5.83 h)	89.7° 04:45	6.42	79%	118.7°
2046-08-12 Sun	100	—	unknown	22:50–04:45 (good, 5.92 h)	89.8° 04:40	6.48	87%	107.6°
2046-08-13 Mon	100	—	unknown	23:00–04:45 (good, 5.75 h)	89.8° 04:35	6.54	93%	96.5°
2046-08-14 Tue	79	—	unknown	23:40–04:45 (good, 5.08 h)	89.6° 04:30	6.59	97%	85.5°
2046-08-15 Wed	71	—	unknown	01:05–04:50 (good, 3.75 h)	89.6° 04:30	6.65	100%	74.7°
2046-08-16 Thu	60	—	unknown	04:25–04:50 (good, 0.42 h)	89.7° 04:25	6.71	100%	64.2°
2046-08-17 Fri	45	—	unknown	22:05–04:50 (marginal, 6.75 h)	89.8° 04:20	6.77	98%	54.1°
2046-08-18 Sat	36	—	unknown	22:05–04:50 (marginal, 6.75 h)	89.7° 04:15	6.82	95%	44.8°
2046-08-19 Sun	35	—	unknown	22:00–04:55 (marginal, 6.92 h)	89.6° 04:10	6.88	90%	36.7°
2046-08-20 Mon	39	—	unknown	22:00–04:55 (marginal, 6.92 h)	89.6° 04:10	6.94	84%	30.7°
2046-08-21 Tue	54	—	unknown	21:55–04:55 (marginal, 7.0 h)	89.8° 04:05	7.0	76%	28.2°
2046-08-22 Wed	76	—	unknown	21:55–22:25 (good, 0.5 h)	89.8° 04:00	7.05	68%	30.1°
2046-08-23 Thu	84	—	unknown	21:55–04:05 (good, 6.17 h)	89.7° 03:55	7.11	58%	35.8°
2046-08-24 Fri	88	—	unknown	21:50–05:00 (good, 7.17 h)	89.5° 03:50	7.17	48%	44.1°
2046-08-25 Sat	94	—	unknown	21:50–05:05 (good, 7.25 h)	89.7° 03:50	7.23	38%	53.9°
2046-08-26 Sun	100	—	unknown	21:45–05:05 (good, 7.33 h)	89.8° 03:45	7.28	28%	64.8°
2046-08-27 Mon	100	—	unknown	21:45–05:05 (good, 7.33 h)	89.8° 03:40	7.34	19%	76.5°
2046-08-28 Tue	100	—	unknown	21:45–05:05 (good, 7.33 h)	89.6° 03:35	7.4	11%	88.8°
2046-08-29 Wed	100	—	unknown	21:40–05:10 (good, 7.5 h)	89.6° 03:35	7.45	5%	101.5°
2046-08-30 Thu	100	—	unknown	21:40–05:10 (good, 7.5 h)	89.7° 03:30	7.51	1%	114.3°
2046-08-31 Fri	100	—	unknown	21:35–05:10 (good, 7.58 h)	89.8° 03:25	7.56	0%	126.9°
2046-09-01 Sat	100	—	unknown	21:35–05:10 (good, 7.58 h)	89.7° 03:20	7.62	2%	138.4°
2046-09-02 Sun	100	—	unknown	21:35–05:15 (good, 7.67 h)	89.6° 03:15	7.68	7%	147.5°
2046-09-03 Mon	100	—	unknown	21:30–05:15 (good, 7.75 h)	89.6° 03:15	7.73	15%	151.7°
2046-09-04 Tue	100	—	unknown	21:30–05:15 (good, 7.75 h)	89.8° 03:10	7.79	24%	149.3°
2046-09-05 Wed	100	—	unknown	21:25–05:20 (good, 7.92 h)	89.8° 03:05	7.84	34%	141.8°
2046-09-06 Thu	100	—	unknown	21:25–05:20 (good, 7.92 h)	89.7° 03:00	7.9	45%	132.0°
2046-09-07 Fri	100	—	unknown	21:25–05:20 (good, 7.92 h)	89.5° 02:55	7.95	56%	121.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-08-09&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.