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: 07-14 (91), 07-13 (89), 07-12 (88), 07-15 (88), 07-11 (87) — by astronomy; check the weather when the night is within four days.

2046-06-20astronomy score per night — click a bar for that night2046-07-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-06-20 Wed	25	—	unknown	02:35–03:40 (good, 1.08 h)	89.6° 08:10	4.42	94%	89.8°
2046-06-21 Thu	23	—	unknown	03:20–03:40 (good, 0.33 h)	89.8° 08:05	4.42	88%	78.8°
2046-06-22 Fri	21	—	unknown	01:25–03:40 (marginal, 2.25 h)	89.8° 08:00	4.43	81%	68.1°
2046-06-23 Sat	22	—	unknown	01:20–03:40 (marginal, 2.33 h)	89.7° 07:55	4.43	73%	57.9°
2046-06-24 Sun	23	—	unknown	01:15–03:40 (marginal, 2.42 h)	89.5° 07:50	4.44	64%	48.3°
2046-06-25 Mon	26	—	unknown	02:35–03:40 (good, 1.08 h)	89.7° 07:50	4.45	55%	39.7°
2046-06-26 Tue	31	—	unknown	02:05–03:40 (good, 1.58 h)	89.8° 07:45	4.46	45%	32.7°
2046-06-27 Wed	37	—	unknown	01:55–03:40 (good, 1.75 h)	89.8° 07:40	4.47	36%	28.6°
2046-06-28 Thu	44	—	unknown	01:35–03:40 (good, 2.08 h)	89.7° 07:35	4.48	27%	28.9°
2046-06-29 Fri	52	—	unknown	01:30–03:40 (good, 2.17 h)	89.5° 07:35	4.5	19%	33.6°
2046-06-30 Sat	59	—	unknown	01:25–03:45 (good, 2.33 h)	89.7° 07:30	4.52	11%	41.6°
2046-07-01 Sun	64	—	unknown	01:20–03:45 (good, 2.42 h)	89.8° 07:25	4.54	6%	51.4°
2046-07-02 Mon	66	—	unknown	01:15–03:45 (good, 2.5 h)	89.8° 07:20	4.56	2%	62.5°
2046-07-03 Tue	68	—	unknown	01:15–03:45 (good, 2.5 h)	89.6° 07:15	4.59	0%	74.3°
2046-07-04 Wed	70	—	unknown	01:10–03:45 (good, 2.58 h)	89.6° 07:15	4.61	1%	86.6°
2046-07-05 Thu	74	—	unknown	01:05–03:50 (good, 2.75 h)	89.8° 07:10	4.64	4%	99.2°
2046-07-06 Fri	75	—	unknown	01:00–03:50 (good, 2.83 h)	89.8° 07:05	4.67	11%	111.7°
2046-07-07 Sat	77	—	unknown	00:55–03:50 (good, 2.92 h)	89.7° 07:00	4.7	19%	123.9°
2046-07-08 Sun	79	—	unknown	00:55–03:50 (good, 2.92 h)	89.5° 06:55	4.74	29%	135.3°
2046-07-09 Mon	82	—	unknown	00:50–03:50 (good, 3.0 h)	89.6° 06:55	4.77	40%	144.8°
2046-07-10 Tue	86	—	unknown	00:45–03:55 (good, 3.17 h)	89.8° 06:50	4.81	51%	150.9°
2046-07-11 Wed	87	—	unknown	00:45–03:55 (good, 3.17 h)	89.8° 06:45	4.84	62%	151.3°
2046-07-12 Thu	88	—	unknown	00:45–03:55 (good, 3.17 h)	89.7° 06:40	4.88	73%	146.0°
2046-07-13 Fri	89	—	unknown	00:40–03:55 (good, 3.25 h)	89.5° 06:40	4.92	82%	137.3°
2046-07-14 Sat	91	—	unknown	00:40–04:00 (good, 3.33 h)	89.7° 06:35	4.96	90%	127.0°
2046-07-15 Sun	88	—	unknown	00:40–04:00 (good, 3.33 h)	89.8° 06:30	5.01	95%	115.9°
2046-07-16 Mon	70	—	unknown	00:45–04:00 (good, 3.25 h)	89.8° 06:25	5.05	99%	104.7°
2046-07-17 Tue	60	—	unknown	00:50–04:05 (good, 3.25 h)	89.6° 06:20	5.09	100%	93.5°
2046-07-18 Wed	51	—	unknown	01:55–04:05 (good, 2.17 h)	89.6° 06:20	5.14	99%	82.4°
2046-07-19 Thu	42	—	unknown	03:05–04:05 (good, 1.0 h)	89.8° 06:15	5.19	96%	71.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-06-20&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.