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: 11-19 (100), 11-20 (100), 11-21 (100), 11-22 (100), 11-23 (100) — by astronomy; check the weather when the night is within four days.

2043-11-16astronomy score per night — click a bar for that night2043-12-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-11-16 Mon	38	—	unknown	18:40–22:30 (marginal, 3.83 h)	89.6° 21:25	10.98	100%	38.3°
2043-11-17 Tue	57	—	unknown	18:40–02:55 (marginal, 8.25 h)	89.8° 21:20	11.01	98%	48.3°
2043-11-18 Wed	70	—	unknown	18:40–20:55 (good, 2.25 h)	89.8° 21:15	11.04	94%	60.1°
2043-11-19 Thu	100	—	unknown	18:35–00:15 (good, 5.67 h)	89.7° 21:10	11.07	87%	72.5°
2043-11-20 Fri	100	—	unknown	18:35–02:00 (good, 7.42 h)	89.5° 21:05	11.09	78%	84.9°
2043-11-21 Sat	100	—	unknown	18:35–02:50 (good, 8.25 h)	89.7° 21:05	11.12	68%	97.0°
2043-11-22 Sun	100	—	unknown	18:35–02:55 (good, 8.33 h)	89.8° 21:00	11.14	57%	108.7°
2043-11-23 Mon	100	—	unknown	18:35–03:00 (good, 8.42 h)	89.8° 20:55	11.16	46%	119.6°
2043-11-24 Tue	100	—	unknown	18:35–02:55 (good, 8.33 h)	89.6° 20:50	11.19	36%	129.7°
2043-11-25 Wed	100	—	unknown	18:35–02:55 (good, 8.33 h)	89.5° 20:50	11.21	27%	138.5°
2043-11-26 Thu	100	—	unknown	18:35–02:55 (good, 8.33 h)	89.7° 20:45	11.23	19%	145.3°
2043-11-27 Fri	100	—	unknown	18:35–02:50 (good, 8.25 h)	89.8° 20:40	11.25	12%	148.9°
2043-11-28 Sat	100	—	unknown	18:35–02:45 (good, 8.17 h)	89.7° 20:35	11.27	6%	148.6°
2043-11-29 Sun	100	—	unknown	18:35–02:40 (good, 8.08 h)	89.6° 20:30	11.29	3%	144.5°
2043-11-30 Mon	100	—	unknown	18:35–02:35 (good, 8.0 h)	89.6° 20:30	11.31	1%	137.7°
2043-12-01 Tue	100	—	unknown	18:35–02:35 (good, 8.0 h)	89.8° 20:25	11.33	0%	129.3°
2043-12-02 Wed	100	—	unknown	18:35–02:30 (good, 7.92 h)	89.8° 20:20	11.35	2%	120.1°
2043-12-03 Thu	100	—	unknown	18:35–02:25 (good, 7.83 h)	89.7° 20:15	11.36	5%	110.3°
2043-12-04 Fri	100	—	unknown	18:35–02:20 (good, 7.75 h)	89.5° 20:10	11.38	10%	100.1°
2043-12-05 Sat	100	—	unknown	18:35–02:15 (good, 7.67 h)	89.7° 20:10	11.39	16%	89.8°
2043-12-06 Sun	100	—	unknown	18:35–02:15 (good, 7.67 h)	89.8° 20:05	11.41	24%	79.3°
2043-12-07 Mon	100	—	unknown	18:35–02:10 (good, 7.58 h)	89.8° 20:00	11.42	33%	68.8°
2043-12-08 Tue	96	—	unknown	18:35–02:05 (good, 7.5 h)	89.6° 19:55	11.43	42%	58.3°
2043-12-09 Wed	87	—	unknown	18:35–02:00 (good, 7.42 h)	89.5° 19:55	11.44	53%	48.3°
2043-12-10 Thu	76	—	unknown	20:35–02:00 (good, 5.42 h)	89.7° 19:50	11.45	64%	39.2°
2043-12-11 Fri	51	—	unknown	18:35–02:20 (marginal, 7.75 h)	89.8° 19:45	11.46	74%	32.6°
2043-12-12 Sat	32	—	unknown	18:35–02:00 (marginal, 7.42 h)	89.7° 19:40	11.47	83%	30.6°
2043-12-13 Sun	27	—	unknown	18:35–01:30 (marginal, 6.92 h)	89.6° 19:35	11.48	91%	34.6°
2043-12-14 Mon	31	—	unknown	18:35–00:20 (marginal, 5.75 h)	89.6° 19:35	11.49	97%	43.3°
2043-12-15 Tue	43	—	unknown	18:35–01:15 (marginal, 6.67 h)	89.8° 19:30	11.49	100%	54.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-11-16&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.