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 HD 189733: 03-31 (46), 03-30 (45), 03-29 (44), 03-28 (43), 03-27 (42) — by astronomy; check the weather when the night is within four days.

2041-03-02astronomy score per night — click a bar for that night2041-03-31

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-03-02 Sat	23	—	unknown	04:35–05:25 (good, 0.83 h)	71.1° 09:40	9.58	0%	58.0°
2041-03-03 Sun	23	—	unknown	04:30–05:20 (good, 0.83 h)	71.1° 09:35	9.54	3%	66.3°
2041-03-04 Mon	24	—	unknown	04:30–05:20 (good, 0.83 h)	71.1° 09:30	9.49	8%	75.5°
2041-03-05 Tue	25	—	unknown	04:25–05:20 (good, 0.92 h)	71.1° 09:25	9.45	15%	85.0°
2041-03-06 Wed	25	—	unknown	04:20–05:15 (good, 0.92 h)	71.1° 09:20	9.4	23%	94.3°
2041-03-07 Thu	26	—	unknown	04:15–05:15 (good, 1.0 h)	71.1° 09:20	9.35	33%	103.2°
2041-03-08 Fri	28	—	unknown	04:15–05:15 (good, 1.0 h)	71.1° 09:15	9.3	43%	111.4°
2041-03-09 Sat	28	—	unknown	04:10–05:10 (good, 1.0 h)	71.1° 09:10	9.25	53%	118.7°
2041-03-10 Sun	28	—	unknown	04:05–05:10 (good, 1.08 h)	71.1° 09:05	9.21	62%	124.8°
2041-03-11 Mon	29	—	unknown	04:05–05:10 (good, 1.08 h)	71.1° 09:00	9.16	71%	129.4°
2041-03-12 Tue	29	—	unknown	04:05–05:05 (good, 1.0 h)	71.1° 09:00	9.11	80%	132.2°
2041-03-13 Wed	27	—	unknown	04:00–05:05 (good, 1.08 h)	71.1° 08:55	9.06	86%	132.7°
2041-03-14 Thu	26	—	unknown	04:00–05:00 (good, 1.0 h)	71.1° 08:50	9.01	92%	131.1°
2041-03-15 Fri	26	—	unknown	03:55–05:00 (good, 1.08 h)	71.1° 08:45	8.96	96%	127.4°
2041-03-16 Sat	27	—	unknown	03:50–05:00 (good, 1.17 h)	71.1° 08:45	8.91	99%	122.1°
2041-03-17 Sun	25	—	unknown	03:50–04:55 (good, 1.08 h)	71.1° 08:40	8.86	100%	115.6°
2041-03-18 Mon	24	—	unknown	03:50–04:55 (good, 1.08 h)	71.1° 08:35	8.81	99%	108.1°
2041-03-19 Tue	23	—	unknown	03:55–04:55 (good, 1.0 h)	71.1° 08:30	8.75	96%	100.0°
2041-03-20 Wed	21	—	unknown	03:55–04:50 (good, 0.92 h)	71.1° 08:25	8.7	91%	91.5°
2041-03-21 Thu	21	—	unknown	04:00–04:50 (good, 0.83 h)	71.1° 08:25	8.65	84%	82.9°
2041-03-22 Fri	21	—	unknown	03:55–04:50 (good, 0.92 h)	71.1° 08:20	8.6	76%	74.3°
2041-03-23 Sat	22	—	unknown	03:40–04:45 (good, 1.08 h)	71.1° 08:15	8.55	66%	66.1°
2041-03-24 Sun	25	—	unknown	03:30–04:45 (good, 1.25 h)	71.1° 08:10	8.49	56%	58.6°
2041-03-25 Mon	28	—	unknown	03:20–04:40 (good, 1.33 h)	71.1° 08:05	8.44	44%	52.4°
2041-03-26 Tue	36	—	unknown	03:00–04:40 (good, 1.67 h)	71.1° 08:05	8.39	33%	48.4°
2041-03-27 Wed	42	—	unknown	03:00–04:40 (good, 1.67 h)	71.1° 08:00	8.33	23%	47.3°
2041-03-28 Thu	43	—	unknown	02:55–04:35 (good, 1.67 h)	71.1° 07:55	8.28	14%	49.6°
2041-03-29 Fri	44	—	unknown	02:50–04:35 (good, 1.75 h)	71.1° 07:50	8.23	7%	54.9°
2041-03-30 Sat	45	—	unknown	02:45–05:35 (good, 1.83 h)	71.1° 08:50	8.17	2%	62.4°
2041-03-31 Sun	46	—	unknown	03:40–05:30 (good, 1.83 h)	71.1° 08:45	8.12	0%	71.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-03-02&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.