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: 08-26 (100), 08-27 (100), 08-28 (100), 08-29 (100), 08-30 (100) — by astronomy; check the weather when the night is within four days.

2046-08-25astronomy score per night — click a bar for that night2046-09-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2046-09-08 Sat	100	—	unknown	21:20–05:20 (good, 8.0 h)	89.7° 02:55	8.01	66%	110.2°
2046-09-09 Sun	100	—	unknown	21:20–05:25 (good, 8.08 h)	89.8° 02:50	8.06	75%	99.1°
2046-09-10 Mon	100	—	unknown	21:15–05:25 (good, 8.17 h)	89.8° 02:45	8.11	83%	88.1°
2046-09-11 Tue	100	—	unknown	22:15–05:25 (good, 7.17 h)	89.6° 02:40	8.17	90%	77.3°
2046-09-12 Wed	100	—	unknown	00:35–05:25 (good, 4.83 h)	89.6° 02:40	8.22	95%	66.8°
2046-09-13 Thu	66	—	unknown	04:10–05:30 (good, 1.33 h)	89.7° 02:35	8.27	98%	56.7°
2046-09-14 Fri	55	—	unknown	21:10–05:30 (marginal, 8.33 h)	89.8° 02:30	8.33	100%	47.2°
2046-09-15 Sat	40	—	unknown	21:05–05:30 (marginal, 8.42 h)	89.7° 02:25	8.38	100%	38.8°
2046-09-16 Sun	34	—	unknown	21:05–01:45 (marginal, 4.67 h)	89.6° 02:20	8.43	97%	32.1°
2046-09-17 Mon	37	—	unknown	21:05–02:15 (marginal, 5.17 h)	89.6° 02:20	8.49	94%	28.5°
2046-09-18 Tue	46	—	unknown	21:00–05:35 (marginal, 8.58 h)	89.8° 02:15	8.54	88%	29.3°
2046-09-19 Wed	57	—	unknown	20:25–05:35 (marginal, 9.17 h)	89.8° 02:10	8.59	82%	34.1°
2046-09-20 Thu	86	—	unknown	21:00–00:40 (good, 3.67 h)	89.7° 02:05	8.64	73%	41.7°
2046-09-21 Fri	92	—	unknown	20:55–04:40 (good, 7.75 h)	89.5° 02:00	8.69	64%	50.9°
2046-09-22 Sat	99	—	unknown	20:55–05:40 (good, 8.75 h)	89.7° 02:00	8.74	54%	61.3°
2046-09-23 Sun	100	—	unknown	20:50–05:40 (good, 8.83 h)	89.8° 01:55	8.79	44%	72.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-08-25&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.