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: 06-12 (33), 06-11 (30), 06-10 (25), 06-09 (21), 06-08 (18) — by astronomy; check the weather when the night is within four days.

2045-05-14astronomy score per night — click a bar for that night2045-06-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-05-14 Sun	5	—	unknown	04:30–04:50 (marginal, 0.33 h)	89.5° 10:35	5.61	4%	29.0°
2045-05-15 Mon	5	—	unknown	04:25–04:50 (marginal, 0.42 h)	89.7° 10:30	5.56	1%	32.5°
2045-05-16 Tue	5	—	unknown	04:20–04:50 (marginal, 0.5 h)	89.8° 10:25	5.5	0%	40.2°
2045-05-17 Wed	6	—	unknown	04:15–04:50 (marginal, 0.58 h)	89.8° 10:20	5.45	2%	50.5°
2045-05-18 Thu	7	—	unknown	04:15–04:50 (marginal, 0.58 h)	89.6° 10:15	5.4	6%	62.1°
2045-05-19 Fri	7	—	unknown	04:10–04:45 (marginal, 0.58 h)	89.6° 10:15	5.35	13%	74.3°
2045-05-20 Sat	8	—	unknown	04:05–04:45 (marginal, 0.67 h)	89.7° 10:10	5.3	22%	86.9°
2045-05-21 Sun	9	—	unknown	03:30–04:45 (marginal, 1.25 h)	89.8° 10:05	5.25	32%	99.5°
2045-05-22 Mon	9	—	unknown	03:25–04:45 (marginal, 1.33 h)	89.7° 10:00	5.2	43%	111.8°
2045-05-23 Tue	10	—	unknown	03:20–04:40 (marginal, 1.33 h)	89.6° 09:55	5.16	55%	123.6°
2045-05-24 Wed	11	—	unknown	03:50–03:55 (good, 0.08 h)	89.6° 09:55	5.11	66%	134.4°
2045-05-25 Thu	11	—	unknown	03:45–03:50 (good, 0.08 h)	89.8° 09:50	5.06	76%	143.6°
2045-05-26 Fri	12	—	unknown	03:40–03:50 (good, 0.17 h)	89.8° 09:45	5.02	84%	149.7°
2045-05-27 Sat	12	—	unknown	03:45–03:50 (good, 0.08 h)	89.7° 09:40	4.98	91%	150.8°
2045-05-28 Sun	13	—	unknown	03:40–03:50 (good, 0.17 h)	89.5° 09:35	4.93	96%	146.8°
2045-05-29 Mon	13	—	unknown	03:40–03:50 (good, 0.17 h)	89.7° 09:35	4.89	99%	139.3°
2045-05-30 Tue	13	—	unknown	03:35–03:45 (good, 0.17 h)	89.8° 09:30	4.86	100%	130.0°
2045-05-31 Wed	14	—	unknown	03:35–03:45 (good, 0.17 h)	89.8° 09:25	4.82	98%	119.9°
2045-06-01 Thu	14	—	unknown	03:35–03:45 (good, 0.17 h)	89.6° 09:20	4.78	95%	109.5°
2045-06-02 Fri	14	—	unknown	03:35–03:45 (good, 0.17 h)	89.6° 09:20	4.75	90%	99.0°
2045-06-03 Sat	14	—	unknown	03:40–03:45 (good, 0.08 h)	89.7° 09:15	4.71	84%	88.5°
2045-06-04 Sun	13	—	unknown	03:35–03:40 (good, 0.08 h)	89.8° 09:10	4.68	76%	78.1°
2045-06-05 Mon	13	—	unknown	03:35–03:40 (good, 0.08 h)	89.7° 09:05	4.65	68%	67.9°
2045-06-06 Tue	14	—	unknown	03:30–03:40 (good, 0.17 h)	89.6° 09:00	4.62	59%	57.9°
2045-06-07 Wed	16	—	unknown	03:20–03:40 (good, 0.33 h)	89.6° 09:00	4.6	49%	48.4°
2045-06-08 Thu	18	—	unknown	03:10–03:40 (good, 0.5 h)	89.8° 08:55	4.57	40%	39.6°
2045-06-09 Fri	21	—	unknown	03:00–03:40 (good, 0.67 h)	89.8° 08:50	4.55	30%	32.6°
2045-06-10 Sat	25	—	unknown	02:40–03:40 (good, 1.0 h)	89.7° 08:45	4.53	21%	29.0°
2045-06-11 Sun	30	—	unknown	02:40–03:40 (good, 1.0 h)	89.5° 08:40	4.51	13%	30.4°
2045-06-12 Mon	33	—	unknown	02:35–03:40 (good, 1.08 h)	89.7° 08:40	4.49	7%	36.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-05-14&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.