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: 06-05 (24), 06-06 (24), 06-08 (24), 06-09 (24), 06-03 (23) — by astronomy; check the weather when the night is within four days.

2044-05-11astronomy score per night — click a bar for that night2044-06-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-05-11 Wed	3	—	unknown	04:05–04:15 (marginal, 0.17 h)	89.6° 10:45	5.76	100%	144.0°
2044-05-12 Thu	3	—	unknown	04:00–04:10 (marginal, 0.17 h)	89.8° 10:40	5.7	99%	136.6°
2044-05-13 Fri	4	—	unknown	04:40–04:55 (marginal, 0.25 h)	89.8° 10:35	5.65	96%	127.8°
2044-05-14 Sat	4	—	unknown	03:55–04:10 (marginal, 0.25 h)	89.7° 10:30	5.6	92%	118.3°
2044-05-15 Sun	4	—	unknown	03:50–04:05 (marginal, 0.25 h)	89.5° 10:30	5.54	86%	108.4°
2044-05-16 Mon	4	—	unknown	03:45–04:05 (marginal, 0.33 h)	89.7° 10:25	5.49	79%	98.3°
2044-05-17 Tue	4	—	unknown	03:45–04:05 (marginal, 0.33 h)	89.8° 10:20	5.44	71%	88.0°
2044-05-18 Wed	4	—	unknown	03:40–04:00 (marginal, 0.33 h)	89.8° 10:15	5.39	62%	77.6°
2044-05-19 Thu	5	—	unknown	03:35–04:00 (marginal, 0.42 h)	89.6° 10:10	5.34	52%	67.2°
2044-05-20 Fri	6	—	unknown	03:30–04:00 (marginal, 0.5 h)	89.6° 10:10	5.29	42%	56.9°
2044-05-21 Sat	7	—	unknown	03:25–03:55 (marginal, 0.5 h)	89.7° 10:05	5.24	32%	47.0°
2044-05-22 Sun	8	—	unknown	03:25–03:55 (marginal, 0.5 h)	89.8° 10:00	5.19	23%	38.1°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-05-11&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.