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 (34), 03-05 (31), 03-06 (31), 03-07 (31), 03-08 (31) — by astronomy; check the weather when the night is within four days.

2047-02-18astronomy score per night — click a bar for that night2047-03-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-02-18 Mon	15	—	unknown	05:20–05:40 (good, 0.33 h)	87.2° 11:25	10.13	32%	86.1°
2047-02-19 Tue	17	—	unknown	05:10–05:40 (good, 0.5 h)	87.2° 11:20	10.09	22%	78.3°
2047-02-20 Wed	20	—	unknown	05:00–05:40 (good, 0.67 h)	87.2° 11:15	10.04	14%	71.1°
2047-02-21 Thu	20	—	unknown	05:00–05:35 (good, 0.58 h)	87.2° 11:15	10.0	8%	64.7°
2047-02-22 Fri	22	—	unknown	04:55–05:35 (good, 0.67 h)	87.2° 11:10	9.96	3%	59.5°
2047-02-23 Sat	23	—	unknown	04:50–05:35 (good, 0.75 h)	87.2° 11:05	9.92	1%	55.8°
2047-02-24 Sun	24	—	unknown	04:45–05:35 (good, 0.83 h)	87.2° 11:00	9.87	0%	53.9°
2047-02-25 Mon	24	—	unknown	04:40–05:30 (good, 0.83 h)	87.2° 10:55	9.83	1%	53.9°
2047-02-26 Tue	25	—	unknown	04:40–05:30 (good, 0.83 h)	87.2° 10:55	9.79	4%	55.7°
2047-02-27 Wed	26	—	unknown	04:35–05:30 (good, 0.92 h)	87.2° 10:50	9.74	9%	59.1°
2047-02-28 Thu	26	—	unknown	04:30–05:25 (good, 0.92 h)	87.2° 10:45	9.7	15%	63.8°
2047-03-01 Fri	27	—	unknown	04:25–05:25 (good, 1.0 h)	87.2° 10:40	9.65	23%	69.4°
2047-03-02 Sat	29	—	unknown	04:20–05:25 (good, 1.08 h)	87.2° 10:35	9.61	31%	75.7°
2047-03-03 Sun	28	—	unknown	04:20–05:20 (good, 1.0 h)	87.2° 10:35	9.56	40%	82.6°
2047-03-04 Mon	30	—	unknown	04:15–05:20 (good, 1.08 h)	87.2° 10:30	9.51	50%	89.7°
2047-03-05 Tue	31	—	unknown	04:10–05:20 (good, 1.17 h)	87.2° 10:25	9.47	60%	97.1°
2047-03-06 Wed	31	—	unknown	04:05–05:15 (good, 1.17 h)	87.2° 10:20	9.42	70%	104.4°
2047-03-07 Thu	31	—	unknown	04:15–05:15 (good, 1.0 h)	87.2° 10:20	9.37	79%	111.4°
2047-03-08 Fri	31	—	unknown	04:10–05:15 (good, 1.08 h)	87.2° 10:15	9.32	87%	117.7°
2047-03-09 Sat	28	—	unknown	04:05–05:10 (good, 1.08 h)	87.2° 10:10	9.28	94%	122.8°
2047-03-10 Sun	28	—	unknown	04:05–05:10 (good, 1.08 h)	87.2° 10:05	9.23	98%	125.8°
2047-03-11 Mon	29	—	unknown	04:00–05:10 (good, 1.17 h)	87.2° 10:00	9.18	100%	126.2°
2047-03-12 Tue	28	—	unknown	03:55–05:05 (good, 1.17 h)	87.2° 10:00	9.13	99%	123.8°
2047-03-13 Wed	29	—	unknown	03:55–05:05 (good, 1.17 h)	87.2° 09:55	9.08	95%	118.9°
2047-03-14 Thu	28	—	unknown	03:50–05:05 (good, 1.25 h)	87.2° 09:50	9.03	88%	112.2°
2047-03-15 Fri	27	—	unknown	03:50–05:00 (good, 1.17 h)	87.2° 09:45	8.98	79%	104.5°
2047-03-16 Sat	28	—	unknown	03:45–05:00 (good, 1.25 h)	87.2° 09:40	8.93	69%	96.2°
2047-03-17 Sun	29	—	unknown	03:40–05:00 (good, 1.33 h)	87.2° 09:40	8.88	58%	87.9°
2047-03-18 Mon	30	—	unknown	03:35–04:55 (good, 1.33 h)	87.2° 09:35	8.83	47%	79.9°
2047-03-19 Tue	34	—	unknown	03:25–04:55 (good, 1.5 h)	87.2° 09:30	8.78	37%	72.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-02-18&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.