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: 05-05 (2), 05-06 (2), 05-07 (2), 05-08 (2), 05-09 (2) — by astronomy; check the weather when the night is within four days.

2033-04-10astronomy score per night — click a bar for that night2033-05-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-04-10 Sun	0	—	unknown	—	89.8° 12:50	7.56	87%	125.9°
2033-04-11 Mon	0	—	unknown	—	89.7° 12:45	7.51	93%	134.0°
2033-04-12 Tue	0	—	unknown	—	89.6° 12:40	7.45	97%	140.6°
2033-04-13 Wed	0	—	unknown	—	89.6° 12:40	7.39	99%	145.0°
2033-04-14 Thu	0	—	unknown	—	89.7° 12:35	7.33	100%	146.1°
2033-04-15 Fri	0	—	unknown	—	89.8° 12:30	7.28	99%	143.6°
2033-04-16 Sat	0	—	unknown	—	89.7° 12:25	7.22	96%	138.0°
2033-04-17 Sun	0	—	unknown	—	89.5° 12:20	7.16	91%	130.2°
2033-04-18 Mon	0	—	unknown	—	89.6° 12:20	7.1	84%	121.1°
2033-04-19 Tue	0	—	unknown	—	89.7° 12:15	7.04	76%	111.1°
2033-04-20 Wed	0	—	unknown	—	89.7° 12:10	6.99	67%	100.5°
2033-04-21 Thu	0	—	unknown	—	89.6° 12:05	6.93	56%	89.4°
2033-04-22 Fri	0	—	unknown	—	89.7° 12:00	6.87	45%	78.1°
2033-04-23 Sat	0	—	unknown	—	89.8° 11:55	6.81	34%	66.8°
2033-04-24 Sun	0	—	unknown	—	89.7° 11:50	6.75	24%	55.8°
2033-04-25 Mon	0	—	unknown	—	89.6° 11:45	6.69	14%	45.7°
2033-04-26 Tue	1	—	unknown	—	89.6° 11:45	6.64	7%	37.7°
2033-04-27 Wed	1	—	unknown	—	89.7° 11:40	6.58	2%	33.9°
2033-04-28 Thu	1	—	unknown	—	89.8° 11:35	6.52	0%	35.7°
2033-04-29 Fri	1	—	unknown	—	89.7° 11:30	6.46	1%	42.1°
2033-04-30 Sat	1	—	unknown	—	89.5° 11:25	6.4	5%	51.4°
2033-05-01 Sun	1	—	unknown	—	89.6° 11:25	6.35	11%	61.8°
2033-05-02 Mon	1	—	unknown	—	89.7° 11:20	6.29	18%	72.6°
2033-05-03 Tue	1	—	unknown	—	89.7° 11:15	6.23	27%	83.4°
2033-05-04 Wed	1	—	unknown	—	89.6° 11:10	6.17	37%	94.0°
2033-05-05 Thu	2	—	unknown	—	89.5° 11:10	6.12	46%	104.3°
2033-05-06 Fri	2	—	unknown	05:00–05:05 (marginal, 0.08 h)	89.7° 11:05	6.06	56%	114.1°
2033-05-07 Sat	2	—	unknown	04:55–05:00 (marginal, 0.08 h)	89.8° 11:00	6.0	66%	123.3°
2033-05-08 Sun	2	—	unknown	04:50–05:00 (marginal, 0.17 h)	89.7° 10:55	5.95	74%	131.7°
2033-05-09 Mon	2	—	unknown	04:50–05:00 (marginal, 0.17 h)	89.6° 10:50	5.89	82%	138.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-04-10&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.