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: 07-28 (100), 07-29 (100), 07-30 (100), 07-31 (100), 08-01 (100) — by astronomy; check the weather when the night is within four days.

2038-07-15astronomy score per night — click a bar for that night2038-08-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-07-15 Thu	63	—	unknown	00:50–04:00 (good, 3.17 h)	89.8° 06:30	5.0	100%	99.8°
2038-07-16 Fri	55	—	unknown	01:10–04:00 (good, 2.83 h)	89.8° 06:25	5.05	100%	89.1°
2038-07-17 Sat	48	—	unknown	02:05–04:05 (good, 2.0 h)	89.6° 06:20	5.09	98%	78.7°
2038-07-18 Sun	42	—	unknown	03:00–04:05 (good, 1.08 h)	89.5° 06:20	5.14	93%	68.7°
2038-07-19 Mon	40	—	unknown	23:40–04:05 (marginal, 4.42 h)	89.7° 06:15	5.18	87%	59.5°
2038-07-20 Tue	40	—	unknown	23:35–04:05 (marginal, 4.5 h)	89.8° 06:10	5.23	80%	51.4°
2038-07-21 Wed	45	—	unknown	02:30–03:55 (good, 1.42 h)	89.7° 06:05	5.28	71%	44.7°
2038-07-22 Thu	61	—	unknown	00:00–04:10 (good, 4.17 h)	89.6° 06:00	5.33	62%	40.2°
2038-07-23 Fri	74	—	unknown	23:55–04:10 (good, 4.25 h)	89.6° 06:00	5.38	53%	38.3°
2038-07-24 Sat	86	—	unknown	23:50–04:15 (good, 4.42 h)	89.7° 05:55	5.43	43%	39.6°
2038-07-25 Sun	89	—	unknown	23:45–04:15 (good, 4.5 h)	89.8° 05:50	5.48	34%	43.6°
2038-07-26 Mon	93	—	unknown	23:40–04:15 (good, 4.58 h)	89.7° 05:45	5.53	25%	49.8°
2038-07-27 Tue	98	—	unknown	23:40–04:20 (good, 4.67 h)	89.5° 05:40	5.58	17%	57.5°
2038-07-28 Wed	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.6° 05:40	5.64	10%	66.4°
2038-07-29 Thu	100	—	unknown	23:30–04:20 (good, 4.83 h)	89.8° 05:35	5.69	5%	76.1°
2038-07-30 Fri	100	—	unknown	23:25–04:20 (good, 4.92 h)	89.8° 05:30	5.74	1%	86.3°
2038-07-31 Sat	100	—	unknown	23:25–04:25 (good, 5.0 h)	89.6° 05:25	5.8	0%	96.8°
2038-08-01 Sun	100	—	unknown	23:20–04:25 (good, 5.08 h)	89.5° 05:25	5.85	1%	107.5°
2038-08-02 Mon	100	—	unknown	23:15–04:25 (good, 5.17 h)	89.7° 05:20	5.91	5%	117.8°
2038-08-03 Tue	100	—	unknown	23:10–04:30 (good, 5.33 h)	89.8° 05:15	5.96	11%	127.3°
2038-08-04 Wed	100	—	unknown	23:05–04:30 (good, 5.42 h)	89.7° 05:10	6.02	19%	135.3°
2038-08-05 Thu	100	—	unknown	23:05–04:30 (good, 5.42 h)	89.6° 05:05	6.08	29%	140.4°
2038-08-06 Fri	100	—	unknown	23:05–04:35 (good, 5.5 h)	89.6° 05:05	6.13	40%	141.6°
2038-08-07 Sat	100	—	unknown	23:00–04:35 (good, 5.58 h)	89.7° 05:00	6.19	51%	138.5°
2038-08-08 Sun	100	—	unknown	23:00–04:35 (good, 5.58 h)	89.8° 04:55	6.25	62%	131.9°
2038-08-09 Mon	100	—	unknown	22:55–04:40 (good, 5.75 h)	89.7° 04:50	6.3	73%	123.3°
2038-08-10 Tue	100	—	unknown	22:55–04:40 (good, 5.75 h)	89.5° 04:45	6.36	82%	113.5°
2038-08-11 Wed	100	—	unknown	23:00–04:40 (good, 5.67 h)	89.6° 04:45	6.42	90%	103.1°
2038-08-12 Thu	100	—	unknown	23:05–04:45 (good, 5.67 h)	89.8° 04:40	6.47	95%	92.6°
2038-08-13 Fri	76	—	unknown	00:00–04:45 (good, 4.75 h)	89.8° 04:35	6.53	99%	82.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-07-15&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.