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 Great Orion Nebula: 09-02 (15), 09-01 (13), 08-31 (9), 08-30 (7), 08-29 (6) — by astronomy; check the weather when the night is within four days.

2032-08-04astronomy score per night — click a bar for that night2032-09-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2032-08-04 Wed	0	—	unknown	—	42.9° 10:00	6.05	2%	41.5°
2032-08-05 Thu	0	—	unknown	—	42.9° 09:55	6.1	0%	51.2°
2032-08-06 Fri	0	—	unknown	—	42.9° 09:55	6.16	1%	61.4°
2032-08-07 Sat	0	—	unknown	—	42.9° 09:50	6.22	3%	71.9°
2032-08-08 Sun	0	—	unknown	—	42.9° 09:45	6.27	7%	82.6°
2032-08-09 Mon	0	—	unknown	—	42.9° 09:40	6.33	12%	93.3°
2032-08-10 Tue	0	—	unknown	—	42.9° 09:35	6.39	19%	104.1°
2032-08-11 Wed	0	—	unknown	—	42.9° 09:35	6.44	27%	115.0°
2032-08-12 Thu	0	—	unknown	—	42.9° 09:30	6.5	36%	125.7°
2032-08-13 Fri	0	—	unknown	—	42.9° 09:25	6.56	46%	136.1°
2032-08-14 Sat	0	—	unknown	—	42.9° 09:20	6.62	56%	145.7°
2032-08-15 Sun	0	—	unknown	—	42.9° 09:15	6.67	67%	153.0°
2032-08-16 Mon	0	—	unknown	—	42.9° 09:15	6.73	77%	155.1°
2032-08-17 Tue	0	—	unknown	—	42.9° 09:10	6.79	86%	150.4°
2032-08-18 Wed	0	—	unknown	—	42.9° 09:05	6.85	93%	140.8°
2032-08-19 Thu	1	—	unknown	—	42.9° 09:00	6.9	98%	128.7°
2032-08-20 Fri	1	—	unknown	—	42.9° 08:55	6.96	100%	115.5°
2032-08-21 Sat	1	—	unknown	—	42.9° 08:55	7.02	99%	101.8°
2032-08-22 Sun	1	—	unknown	—	42.9° 08:50	7.08	95%	88.1°
2032-08-23 Mon	1	—	unknown	—	42.9° 08:45	7.13	88%	74.6°
2032-08-24 Tue	1	—	unknown	—	42.9° 08:40	7.19	80%	61.7°
2032-08-25 Wed	1	—	unknown	—	42.9° 08:40	7.25	70%	49.6°
2032-08-26 Thu	2	—	unknown	—	42.9° 08:35	7.3	59%	38.8°
2032-08-27 Fri	2	—	unknown	04:55–05:05 (marginal, 0.17 h)	42.9° 08:30	7.36	49%	30.1°
2032-08-28 Sat	4	—	unknown	04:40–05:05 (marginal, 0.42 h)	42.9° 08:25	7.42	39%	25.2°
2032-08-29 Sun	6	—	unknown	04:35–05:10 (marginal, 0.58 h)	42.9° 08:20	7.47	29%	25.6°
2032-08-30 Mon	7	—	unknown	04:35–05:10 (marginal, 0.58 h)	42.9° 08:20	7.53	21%	31.0°
2032-08-31 Tue	9	—	unknown	05:05–05:10 (good, 0.08 h)	42.9° 08:15	7.59	14%	39.2°
2032-09-01 Wed	13	—	unknown	05:00–05:15 (good, 0.25 h)	42.9° 08:10	7.64	8%	48.7°
2032-09-02 Thu	15	—	unknown	04:50–05:15 (good, 0.42 h)	42.9° 08:05	7.7	4%	58.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2032-08-04&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.