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: 10-27 (100), 10-28 (100), 10-29 (100), 10-30 (100), 10-31 (100) — by astronomy; check the weather when the night is within four days.

2029-10-23astronomy score per night — click a bar for that night2029-11-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-10-23 Tue	45	—	unknown	20:05–00:40 (marginal, 4.58 h)	89.7° 23:55	10.17	98%	35.2°
2029-10-24 Wed	58	—	unknown	20:00–05:35 (marginal, 9.58 h)	89.6° 23:50	10.21	94%	42.6°
2029-10-25 Thu	93	—	unknown	20:00–22:20 (good, 2.33 h)	89.5° 23:45	10.25	89%	51.5°
2029-10-26 Fri	99	—	unknown	20:00–01:00 (good, 5.0 h)	89.6° 23:45	10.29	83%	61.3°
2029-10-27 Sat	100	—	unknown	20:00–03:30 (good, 7.5 h)	89.7° 23:40	10.32	75%	71.6°
2029-10-28 Sun	100	—	unknown	18:55–04:00 (good, 9.08 h)	89.7° 22:35	10.36	66%	82.4°
2029-10-29 Mon	100	—	unknown	18:55–04:20 (good, 9.42 h)	89.6° 22:30	10.4	56%	93.4°
2029-10-30 Tue	100	—	unknown	18:55–04:25 (good, 9.5 h)	89.5° 22:30	10.44	45%	104.8°
2029-10-31 Wed	100	—	unknown	18:55–04:25 (good, 9.5 h)	89.6° 22:25	10.48	35%	116.2°
2029-11-01 Thu	100	—	unknown	18:50–04:25 (good, 9.58 h)	89.7° 22:20	10.51	25%	127.6°
2029-11-02 Fri	100	—	unknown	18:50–04:25 (good, 9.58 h)	89.7° 22:15	10.55	15%	138.3°
2029-11-03 Sat	100	—	unknown	18:50–04:20 (good, 9.5 h)	89.6° 22:10	10.58	8%	147.0°
2029-11-04 Sun	100	—	unknown	18:50–04:15 (good, 9.42 h)	89.5° 22:10	10.62	3%	151.0°
2029-11-05 Mon	100	—	unknown	18:50–04:15 (good, 9.42 h)	89.7° 22:05	10.65	0%	148.3°
2029-11-06 Tue	100	—	unknown	18:45–04:10 (good, 9.42 h)	89.7° 22:00	10.69	1%	140.1°
2029-11-07 Wed	100	—	unknown	18:45–04:05 (good, 9.33 h)	89.7° 21:55	10.72	4%	129.1°
2029-11-08 Thu	100	—	unknown	18:45–04:00 (good, 9.25 h)	89.5° 21:50	10.75	11%	117.0°
2029-11-09 Fri	100	—	unknown	18:45–03:55 (good, 9.17 h)	89.6° 21:50	10.79	19%	104.7°
2029-11-10 Sat	100	—	unknown	18:45–03:55 (good, 9.17 h)	89.7° 21:45	10.82	28%	92.6°
2029-11-11 Sun	100	—	unknown	18:40–03:50 (good, 9.17 h)	89.7° 21:40	10.85	39%	80.8°
2029-11-12 Mon	100	—	unknown	18:40–03:45 (good, 9.08 h)	89.6° 21:35	10.88	49%	69.6°
2029-11-13 Tue	97	—	unknown	18:40–03:40 (good, 9.0 h)	89.5° 21:35	10.91	59%	59.0°
2029-11-14 Wed	90	—	unknown	18:40–03:35 (good, 8.92 h)	89.6° 21:30	10.94	68%	49.1°
2029-11-15 Thu	83	—	unknown	02:35–03:35 (good, 1.0 h)	89.7° 21:25	10.97	77%	40.4°
2029-11-16 Fri	55	—	unknown	18:40–04:05 (marginal, 9.42 h)	89.7° 21:20	11.0	84%	33.4°
2029-11-17 Sat	37	—	unknown	18:40–03:40 (marginal, 9.0 h)	89.6° 21:15	11.02	91%	29.4°
2029-11-18 Sun	29	—	unknown	00:20–03:15 (marginal, 2.92 h)	89.5° 21:15	11.05	95%	29.5°
2029-11-19 Mon	31	—	unknown	18:35–21:10 (marginal, 2.58 h)	89.7° 21:10	11.08	98%	33.6°
2029-11-20 Tue	40	—	unknown	18:35–23:30 (marginal, 4.92 h)	89.7° 21:05	11.1	100%	40.6°
2029-11-21 Wed	55	—	unknown	18:35–02:40 (marginal, 8.08 h)	89.7° 21:00	11.13	100%	49.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-10-23&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.