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: 03-19 (42), 03-20 (42), 03-17 (40), 03-18 (40), 03-16 (36) — by astronomy; check the weather when the night is within four days.

2042-02-19astronomy score per night — click a bar for that night2042-03-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-02-19 Wed	20	—	unknown	05:05–05:40 (good, 0.58 h)	87.3° 11:20	10.08	0%	62.9°
2042-02-20 Thu	21	—	unknown	05:00–05:40 (good, 0.67 h)	87.3° 11:15	10.04	1%	61.2°
2042-02-21 Fri	21	—	unknown	04:55–05:35 (good, 0.67 h)	87.2° 11:10	9.99	4%	61.7°
2042-02-22 Sat	21	—	unknown	04:55–05:35 (good, 0.67 h)	87.2° 11:10	9.95	10%	64.2°
2042-02-23 Sun	23	—	unknown	04:50–05:35 (good, 0.75 h)	87.3° 11:05	9.91	18%	68.5°
2042-02-24 Mon	23	—	unknown	04:45–05:30 (good, 0.75 h)	87.3° 11:00	9.86	28%	73.9°
2042-02-25 Tue	25	—	unknown	04:40–05:30 (good, 0.83 h)	87.3° 10:55	9.82	39%	80.0°
2042-02-26 Wed	25	—	unknown	04:35–05:30 (good, 0.92 h)	87.2° 10:50	9.78	50%	86.4°
2042-02-27 Thu	26	—	unknown	04:35–05:30 (good, 0.92 h)	87.2° 10:50	9.73	60%	92.8°
2042-02-28 Fri	26	—	unknown	04:30–05:25 (good, 0.92 h)	87.3° 10:45	9.69	70%	98.9°
2042-03-01 Sat	26	—	unknown	04:40–05:25 (good, 0.75 h)	87.3° 10:40	9.64	79%	104.6°
2042-03-02 Sun	23	—	unknown	04:35–05:25 (good, 0.83 h)	87.3° 10:35	9.6	86%	109.5°
2042-03-03 Mon	23	—	unknown	04:30–05:20 (good, 0.83 h)	87.2° 10:30	9.55	92%	113.6°
2042-03-04 Tue	23	—	unknown	04:30–05:20 (good, 0.83 h)	87.3° 10:30	9.5	97%	116.6°
2042-03-05 Wed	24	—	unknown	04:25–05:20 (good, 0.92 h)	87.3° 10:25	9.46	99%	118.4°
2042-03-06 Thu	24	—	unknown	04:20–05:15 (good, 0.92 h)	87.3° 10:20	9.41	100%	118.9°
2042-03-07 Fri	25	—	unknown	04:15–05:15 (good, 1.0 h)	87.3° 10:15	9.36	99%	118.0°
2042-03-08 Sat	25	—	unknown	04:15–05:15 (good, 1.0 h)	87.2° 10:15	9.31	96%	115.9°
2042-03-09 Sun	24	—	unknown	04:10–05:10 (good, 1.0 h)	87.3° 10:10	9.27	92%	112.6°
2042-03-10 Mon	24	—	unknown	04:10–05:10 (good, 1.0 h)	87.3° 10:05	9.22	86%	108.4°
2042-03-11 Tue	25	—	unknown	04:05–05:10 (good, 1.08 h)	87.3° 10:00	9.17	78%	103.4°
2042-03-12 Wed	26	—	unknown	04:00–05:05 (good, 1.08 h)	87.2° 09:55	9.12	70%	97.9°
2042-03-13 Thu	27	—	unknown	03:55–05:05 (good, 1.17 h)	87.2° 09:55	9.07	60%	92.0°
2042-03-14 Fri	29	—	unknown	03:50–05:05 (good, 1.25 h)	87.3° 09:50	9.02	50%	85.9°
2042-03-15 Sat	31	—	unknown	03:40–05:00 (good, 1.33 h)	87.3° 09:45	8.97	40%	79.8°
2042-03-16 Sun	36	—	unknown	03:25–05:00 (good, 1.58 h)	87.3° 09:40	8.92	30%	73.9°
2042-03-17 Mon	40	—	unknown	03:20–04:55 (good, 1.58 h)	87.2° 09:35	8.87	20%	68.6°
2042-03-18 Tue	40	—	unknown	03:20–04:55 (good, 1.58 h)	87.3° 09:35	8.82	11%	64.4°
2042-03-19 Wed	42	—	unknown	03:15–04:55 (good, 1.67 h)	87.3° 09:30	8.77	5%	61.7°
2042-03-20 Thu	42	—	unknown	03:10–04:50 (good, 1.67 h)	87.3° 09:25	8.72	1%	61.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-02-19&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.