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: 07-22 (100), 07-23 (100), 07-24 (100), 07-25 (100), 07-26 (100) — by astronomy; check the weather when the night is within four days.

2044-07-07astronomy score per night — click a bar for that night2044-08-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-07-07 Thu	73	—	unknown	01:05–03:50 (good, 2.75 h)	89.8° 07:00	4.72	95%	123.2°
2044-07-08 Fri	63	—	unknown	01:05–03:50 (good, 2.75 h)	89.8° 06:55	4.75	98%	113.4°
2044-07-09 Sat	58	—	unknown	01:10–03:55 (good, 2.75 h)	89.7° 06:50	4.79	100%	103.3°
2044-07-10 Sun	51	—	unknown	01:15–03:55 (good, 2.67 h)	89.5° 06:45	4.82	100%	93.0°
2044-07-11 Mon	44	—	unknown	02:00–03:55 (good, 1.92 h)	89.7° 06:45	4.86	97%	82.6°
2044-07-12 Tue	39	—	unknown	03:00–03:55 (good, 0.92 h)	89.8° 06:40	4.9	94%	72.2°
2044-07-13 Wed	35	—	unknown	00:05–04:00 (marginal, 3.92 h)	89.8° 06:35	4.94	88%	61.9°
2044-07-14 Thu	34	—	unknown	00:00–04:00 (marginal, 4.0 h)	89.6° 06:30	4.98	81%	51.9°
2044-07-15 Fri	35	—	unknown	23:50–04:00 (marginal, 4.17 h)	89.5° 06:30	5.03	72%	42.7°
2044-07-16 Sat	40	—	unknown	03:20–03:55 (good, 0.58 h)	89.7° 06:25	5.07	62%	34.9°
2044-07-17 Sun	50	—	unknown	00:45–04:05 (good, 3.33 h)	89.8° 06:20	5.11	52%	30.2°
2044-07-18 Mon	67	—	unknown	00:10–04:05 (good, 3.92 h)	89.7° 06:15	5.16	41%	30.4°
2044-07-19 Tue	80	—	unknown	00:10–04:05 (good, 3.92 h)	89.6° 06:10	5.21	30%	35.9°
2044-07-20 Wed	91	—	unknown	00:05–04:10 (good, 4.08 h)	89.6° 06:10	5.26	20%	45.1°
2044-07-21 Thu	96	—	unknown	00:00–04:10 (good, 4.17 h)	89.8° 06:05	5.3	12%	56.4°
2044-07-22 Fri	100	—	unknown	23:55–04:10 (good, 4.25 h)	89.8° 06:00	5.35	5%	68.8°
2044-07-23 Sat	100	—	unknown	23:50–04:10 (good, 4.33 h)	89.7° 05:55	5.4	1%	81.8°
2044-07-24 Sun	100	—	unknown	23:50–04:15 (good, 4.42 h)	89.5° 05:50	5.45	0%	94.9°
2044-07-25 Mon	100	—	unknown	23:45–04:15 (good, 4.5 h)	89.7° 05:50	5.51	2%	107.8°
2044-07-26 Tue	100	—	unknown	23:40–04:15 (good, 4.58 h)	89.8° 05:45	5.56	7%	120.1°
2044-07-27 Wed	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.8° 05:40	5.61	14%	131.3°
2044-07-28 Thu	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.6° 05:35	5.67	22%	140.9°
2044-07-29 Fri	100	—	unknown	23:30–04:20 (good, 4.83 h)	89.5° 05:35	5.72	32%	147.8°
2044-07-30 Sat	100	—	unknown	23:30–04:25 (good, 4.92 h)	89.7° 05:30	5.77	42%	150.5°
2044-07-31 Sun	100	—	unknown	23:25–04:25 (good, 5.0 h)	89.8° 05:25	5.83	52%	148.5°
2044-08-01 Mon	100	—	unknown	23:25–04:25 (good, 5.0 h)	89.8° 05:20	5.88	62%	142.7°
2044-08-02 Tue	100	—	unknown	23:20–04:30 (good, 5.17 h)	89.6° 05:15	5.94	71%	134.8°
2044-08-03 Wed	100	—	unknown	23:15–04:30 (good, 5.25 h)	89.6° 05:15	5.99	79%	125.8°
2044-08-04 Thu	100	—	unknown	23:15–04:30 (good, 5.25 h)	89.8° 05:10	6.05	86%	116.1°
2044-08-05 Fri	100	—	unknown	23:20–04:35 (good, 5.25 h)	89.8° 05:05	6.11	92%	106.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-07-07&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.