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: 07-17 (100), 07-18 (100), 07-19 (100), 07-20 (100), 07-21 (100) — by astronomy; check the weather when the night is within four days.

2029-06-23astronomy score per night — click a bar for that night2029-07-22

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-06-23 Sat	42	—	unknown	02:00–03:40 (good, 1.67 h)	89.7° 07:55	4.43	94%	134.8°
2029-06-24 Sun	42	—	unknown	02:00–03:40 (good, 1.67 h)	89.7° 07:50	4.44	98%	123.5°
2029-06-25 Mon	39	—	unknown	02:00–03:40 (good, 1.67 h)	89.5° 07:45	4.45	100%	111.6°
2029-06-26 Tue	34	—	unknown	02:05–03:40 (good, 1.58 h)	89.6° 07:45	4.46	99%	99.5°
2029-06-27 Wed	29	—	unknown	02:35–03:40 (good, 1.08 h)	89.7° 07:40	4.47	96%	87.5°
2029-06-28 Thu	26	—	unknown	03:35–03:40 (good, 0.08 h)	89.7° 07:35	4.49	91%	76.0°
2029-06-29 Fri	24	—	unknown	01:00–03:40 (marginal, 2.67 h)	89.6° 07:30	4.5	84%	64.9°
2029-06-30 Sat	25	—	unknown	00:55–03:45 (marginal, 2.83 h)	89.5° 07:25	4.52	76%	54.4°
2029-07-01 Sun	27	—	unknown	00:50–03:45 (marginal, 2.92 h)	89.6° 07:25	4.54	67%	44.9°
2029-07-02 Mon	30	—	unknown	03:10–03:45 (good, 0.58 h)	89.7° 07:20	4.57	58%	36.8°
2029-07-03 Tue	36	—	unknown	01:40–03:45 (good, 2.08 h)	89.7° 07:15	4.59	48%	30.9°
2029-07-04 Wed	45	—	unknown	01:25–03:45 (good, 2.33 h)	89.6° 07:10	4.62	39%	28.5°
2029-07-05 Thu	55	—	unknown	01:05–03:50 (good, 2.75 h)	89.5° 07:10	4.65	30%	30.5°
2029-07-06 Fri	65	—	unknown	01:00–03:50 (good, 2.83 h)	89.6° 07:05	4.68	21%	36.2°
2029-07-07 Sat	72	—	unknown	00:55–03:50 (good, 2.92 h)	89.7° 07:00	4.71	14%	44.3°
2029-07-08 Sun	79	—	unknown	00:50–03:50 (good, 3.0 h)	89.7° 06:55	4.74	8%	53.9°
2029-07-09 Mon	82	—	unknown	00:50–03:50 (good, 3.0 h)	89.5° 06:50	4.77	3%	64.4°
2029-07-10 Tue	86	—	unknown	00:45–03:55 (good, 3.17 h)	89.5° 06:50	4.81	1%	75.5°
2029-07-11 Wed	89	—	unknown	00:40–03:55 (good, 3.25 h)	89.7° 06:45	4.85	0%	87.1°
2029-07-12 Thu	90	—	unknown	00:35–03:55 (good, 3.33 h)	89.7° 06:40	4.89	2%	98.9°
2029-07-13 Fri	93	—	unknown	00:35–03:55 (good, 3.33 h)	89.7° 06:35	4.93	6%	110.9°
2029-07-14 Sat	96	—	unknown	00:30–04:00 (good, 3.5 h)	89.5° 06:30	4.97	13%	122.6°
2029-07-15 Sun	98	—	unknown	00:25–04:00 (good, 3.58 h)	89.6° 06:30	5.01	21%	133.7°
2029-07-16 Mon	99	—	unknown	00:20–04:00 (good, 3.67 h)	89.7° 06:25	5.05	31%	143.4°
2029-07-17 Tue	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.7° 06:20	5.1	42%	150.0°
2029-07-18 Wed	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.6° 06:15	5.14	54%	151.2°
2029-07-19 Thu	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.5° 06:15	5.19	65%	146.4°
2029-07-20 Fri	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.6° 06:10	5.24	76%	137.7°
2029-07-21 Sat	100	—	unknown	00:10–04:10 (good, 4.0 h)	89.7° 06:05	5.29	85%	127.0°
2029-07-22 Sun	100	—	unknown	00:10–04:10 (good, 4.0 h)	89.7° 06:00	5.34	92%	115.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-06-23&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.