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: 06-21 (41), 06-20 (35), 06-19 (29), 06-18 (25), 06-05 (24) — by astronomy; check the weather when the night is within four days.

2044-05-23astronomy score per night — click a bar for that night2044-06-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-05-23 Mon	10	—	unknown	03:50–03:55 (good, 0.08 h)	89.7° 09:55	5.14	14%	31.7°
2044-05-24 Tue	11	—	unknown	03:50–03:55 (good, 0.08 h)	89.6° 09:50	5.1	7%	30.2°
2044-05-25 Wed	12	—	unknown	03:45–03:50 (good, 0.08 h)	89.6° 09:50	5.05	2%	34.6°
2044-05-26 Thu	13	—	unknown	03:40–03:50 (good, 0.17 h)	89.8° 09:45	5.01	0%	43.4°
2044-05-27 Fri	14	—	unknown	03:35–03:50 (good, 0.25 h)	89.8° 09:40	4.97	1%	54.7°
2044-05-28 Sat	15	—	unknown	03:35–03:50 (good, 0.25 h)	89.7° 09:35	4.92	5%	67.1°
2044-05-29 Sun	16	—	unknown	03:30–03:50 (good, 0.33 h)	89.5° 09:35	4.88	11%	79.9°
2044-05-30 Mon	17	—	unknown	03:25–03:45 (good, 0.33 h)	89.7° 09:30	4.85	20%	92.6°
2044-05-31 Tue	18	—	unknown	03:20–03:45 (good, 0.42 h)	89.8° 09:25	4.81	30%	105.0°
2044-06-01 Wed	19	—	unknown	03:15–03:45 (good, 0.5 h)	89.8° 09:20	4.77	41%	116.8°
2044-06-02 Thu	21	—	unknown	03:15–03:45 (good, 0.5 h)	89.6° 09:15	4.74	52%	127.7°
2044-06-03 Fri	23	—	unknown	03:10–03:45 (good, 0.58 h)	89.6° 09:15	4.7	62%	137.3°
2044-06-04 Sat	23	—	unknown	03:05–03:40 (good, 0.58 h)	89.7° 09:10	4.67	72%	144.9°
2044-06-05 Sun	24	—	unknown	03:00–03:40 (good, 0.67 h)	89.8° 09:05	4.64	80%	149.4°
2044-06-06 Mon	24	—	unknown	03:05–03:40 (good, 0.58 h)	89.7° 09:00	4.62	88%	149.6°
2044-06-07 Tue	23	—	unknown	03:00–03:40 (good, 0.67 h)	89.6° 08:55	4.59	93%	145.5°
2044-06-08 Wed	24	—	unknown	03:00–03:40 (good, 0.67 h)	89.6° 08:55	4.56	97%	138.7°
2044-06-09 Thu	24	—	unknown	02:55–03:40 (good, 0.75 h)	89.8° 08:50	4.54	99%	130.2°
2044-06-10 Fri	24	—	unknown	02:50–03:40 (good, 0.83 h)	89.8° 08:45	4.52	100%	120.8°
2044-06-11 Sat	23	—	unknown	02:55–03:40 (good, 0.75 h)	89.7° 08:40	4.5	98%	111.0°
2044-06-12 Sun	22	—	unknown	02:55–03:40 (good, 0.75 h)	89.5° 08:35	4.48	95%	100.8°
2044-06-13 Mon	20	—	unknown	03:00–03:40 (good, 0.67 h)	89.7° 08:35	4.47	90%	90.6°
2044-06-14 Tue	19	—	unknown	03:05–03:40 (good, 0.58 h)	89.8° 08:30	4.46	84%	80.2°
2044-06-15 Wed	19	—	unknown	03:25–03:40 (good, 0.25 h)	89.8° 08:25	4.45	76%	69.9°
2044-06-16 Thu	20	—	unknown	03:20–03:40 (good, 0.33 h)	89.6° 08:20	4.44	68%	59.6°
2044-06-17 Fri	22	—	unknown	02:45–03:40 (good, 0.92 h)	89.6° 08:20	4.43	58%	49.7°
2044-06-18 Sat	25	—	unknown	02:35–03:40 (good, 1.08 h)	89.7° 08:15	4.42	48%	40.6°
2044-06-19 Sun	29	—	unknown	02:25–03:40 (good, 1.25 h)	89.8° 08:10	4.42	37%	33.4°
2044-06-20 Mon	35	—	unknown	02:00–03:40 (good, 1.67 h)	89.7° 08:05	4.42	27%	29.9°
2044-06-21 Tue	41	—	unknown	02:00–03:40 (good, 1.67 h)	89.6° 08:00	4.42	17%	31.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-05-23&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.