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 V1057 Cyg: 03-11 (35), 03-08 (34), 03-10 (34), 03-12 (34), 03-09 (33) — by astronomy; check the weather when the night is within four days.

2041-02-22astronomy score per night — click a bar for that night2041-03-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-02-22 Fri	17	—	unknown	05:10–05:35 (good, 0.42 h)	87.3° 11:05	9.94	61%	99.7°
2041-02-23 Sat	18	—	unknown	05:00–05:35 (good, 0.58 h)	87.2° 11:05	9.9	51%	93.8°
2041-02-24 Sun	19	—	unknown	04:55–05:30 (good, 0.58 h)	87.3° 11:00	9.85	40%	87.5°
2041-02-25 Mon	21	—	unknown	04:50–05:30 (good, 0.67 h)	87.3° 10:55	9.81	29%	81.1°
2041-02-26 Tue	24	—	unknown	04:35–05:30 (good, 0.92 h)	87.3° 10:50	9.77	20%	74.9°
2041-02-27 Wed	26	—	unknown	04:30–05:25 (good, 0.92 h)	87.2° 10:45	9.72	11%	69.5°
2041-02-28 Thu	27	—	unknown	04:30–05:25 (good, 0.92 h)	87.3° 10:45	9.68	5%	65.2°
2041-03-01 Fri	28	—	unknown	04:25–05:25 (good, 1.0 h)	87.3° 10:40	9.63	1%	62.6°
2041-03-02 Sat	29	—	unknown	04:20–05:25 (good, 1.08 h)	87.3° 10:35	9.58	0%	62.1°
2041-03-03 Sun	29	—	unknown	04:15–05:20 (good, 1.08 h)	87.3° 10:30	9.54	3%	63.7°
2041-03-04 Mon	30	—	unknown	04:15–05:20 (good, 1.08 h)	87.2° 10:30	9.49	8%	67.0°
2041-03-05 Tue	31	—	unknown	04:10–05:20 (good, 1.17 h)	87.3° 10:25	9.45	15%	71.6°
2041-03-06 Wed	31	—	unknown	04:05–05:15 (good, 1.17 h)	87.3° 10:20	9.4	23%	77.0°
2041-03-07 Thu	32	—	unknown	04:00–05:15 (good, 1.25 h)	87.3° 10:15	9.35	33%	82.9°
2041-03-08 Fri	34	—	unknown	03:55–05:15 (good, 1.33 h)	87.3° 10:10	9.3	43%	88.8°
2041-03-09 Sat	33	—	unknown	03:55–05:10 (good, 1.25 h)	87.2° 10:10	9.25	53%	94.7°
2041-03-10 Sun	34	—	unknown	03:50–05:10 (good, 1.33 h)	87.3° 10:05	9.21	62%	100.2°
2041-03-11 Mon	35	—	unknown	03:55–05:10 (good, 1.25 h)	87.3° 10:00	9.16	71%	105.3°
2041-03-12 Tue	34	—	unknown	03:55–05:05 (good, 1.17 h)	87.3° 09:55	9.11	80%	109.7°
2041-03-13 Wed	31	—	unknown	03:50–05:05 (good, 1.25 h)	87.2° 09:50	9.06	86%	113.4°
2041-03-14 Thu	30	—	unknown	03:45–05:00 (good, 1.25 h)	87.3° 09:50	9.01	92%	116.1°
2041-03-15 Fri	30	—	unknown	03:45–05:00 (good, 1.25 h)	87.3° 09:45	8.96	96%	117.6°
2041-03-16 Sat	31	—	unknown	03:40–05:00 (good, 1.33 h)	87.3° 09:40	8.91	99%	117.9°
2041-03-17 Sun	30	—	unknown	03:40–04:55 (good, 1.25 h)	87.3° 09:35	8.86	100%	116.9°
2041-03-18 Mon	30	—	unknown	03:35–04:55 (good, 1.33 h)	87.2° 09:35	8.81	99%	114.5°
2041-03-19 Tue	30	—	unknown	03:35–04:55 (good, 1.33 h)	87.3° 09:30	8.75	96%	111.0°
2041-03-20 Wed	29	—	unknown	03:30–04:50 (good, 1.33 h)	87.3° 09:25	8.7	91%	106.5°
2041-03-21 Thu	29	—	unknown	03:30–04:50 (good, 1.33 h)	87.3° 09:20	8.65	84%	101.2°
2041-03-22 Fri	30	—	unknown	03:25–04:50 (good, 1.42 h)	87.3° 09:15	8.6	76%	95.4°
2041-03-23 Sat	31	—	unknown	03:15–04:45 (good, 1.5 h)	87.2° 09:15	8.55	66%	89.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-02-22&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.