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: 07-30 (100), 07-31 (100), 08-01 (100), 08-02 (100), 08-03 (100) — by astronomy; check the weather when the night is within four days.

2046-07-26astronomy score per night — click a bar for that night2046-08-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-07-26 Thu	79	—	unknown	23:45–04:15 (good, 4.5 h)	89.7° 05:45	5.53	42%	31.5°
2046-07-27 Fri	85	—	unknown	23:40–04:20 (good, 4.67 h)	89.5° 05:45	5.59	33%	38.3°
2046-07-28 Sat	91	—	unknown	23:35–04:20 (good, 4.75 h)	89.7° 05:40	5.64	23%	47.4°
2046-07-29 Sun	97	—	unknown	23:30–04:20 (good, 4.83 h)	89.8° 05:35	5.69	15%	58.0°
2046-07-30 Mon	100	—	unknown	23:25–04:25 (good, 5.0 h)	89.8° 05:30	5.75	8%	69.5°
2046-07-31 Tue	100	—	unknown	23:25–04:25 (good, 5.0 h)	89.6° 05:25	5.8	3%	81.7°
2046-08-01 Wed	100	—	unknown	23:20–04:25 (good, 5.08 h)	89.6° 05:25	5.86	0%	94.3°
2046-08-02 Thu	100	—	unknown	23:15–04:25 (good, 5.17 h)	89.7° 05:20	5.91	0%	107.1°
2046-08-03 Fri	100	—	unknown	23:10–04:30 (good, 5.33 h)	89.8° 05:15	5.97	3%	119.8°
2046-08-04 Sat	100	—	unknown	23:05–04:30 (good, 5.42 h)	89.7° 05:10	6.02	9%	131.8°
2046-08-05 Sun	100	—	unknown	23:05–04:30 (good, 5.42 h)	89.6° 05:05	6.08	17%	142.4°
2046-08-06 Mon	100	—	unknown	23:00–04:35 (good, 5.58 h)	89.6° 05:05	6.14	27%	149.8°
2046-08-07 Tue	100	—	unknown	22:55–04:35 (good, 5.67 h)	89.8° 05:00	6.19	37%	151.8°
2046-08-08 Wed	100	—	unknown	22:55–04:35 (good, 5.67 h)	89.8° 04:55	6.25	49%	147.6°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-07-26&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.