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: 08-17 (100), 08-18 (100), 08-19 (100), 08-20 (100), 08-21 (100) — by astronomy; check the weather when the night is within four days.

2047-08-17astronomy score per night — click a bar for that night2047-09-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-08-17 Sat	100	—	unknown	22:05–04:50 (good, 6.75 h)	87.2° 00:35	6.75	13%	106.7°
2047-08-18 Sun	100	—	unknown	22:05–04:50 (good, 6.75 h)	87.2° 00:35	6.81	7%	113.4°
2047-08-19 Mon	100	—	unknown	22:00–04:55 (good, 6.92 h)	87.2° 00:30	6.87	3%	119.4°
2047-08-20 Tue	100	—	unknown	22:00–04:55 (good, 6.92 h)	87.2° 00:25	6.93	0%	123.9°
2047-08-21 Wed	100	—	unknown	21:55–04:55 (good, 7.0 h)	87.2° 00:20	6.98	0%	126.5°
2047-08-22 Thu	100	—	unknown	21:55–05:00 (good, 7.08 h)	87.2° 00:15	7.04	3%	126.5°
2047-08-23 Fri	100	—	unknown	21:55–05:00 (good, 7.08 h)	87.2° 00:15	7.1	9%	124.0°
2047-08-24 Sat	100	—	unknown	21:50–05:00 (good, 7.17 h)	87.2° 00:10	7.15	16%	119.2°
2047-08-25 Sun	100	—	unknown	21:50–05:00 (good, 7.17 h)	87.2° 00:05	7.21	26%	112.7°
2047-08-26 Mon	100	—	unknown	21:50–05:05 (good, 7.25 h)	87.2° 00:00	7.27	36%	105.0°
2047-08-27 Tue	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.2° 00:00	7.33	48%	96.8°
2047-08-28 Wed	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.2° 23:55	7.38	59%	88.4°
2047-08-29 Thu	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:50	7.44	70%	80.2°
2047-08-30 Fri	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:45	7.49	80%	72.5°
2047-08-31 Sat	93	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:40	7.55	88%	65.6°
2047-09-01 Sun	85	—	unknown	01:10–05:10 (good, 4.0 h)	87.2° 23:40	7.61	94%	59.9°
2047-09-02 Mon	57	—	unknown	21:35–05:15 (marginal, 7.67 h)	87.2° 23:35	7.66	98%	55.7°
2047-09-03 Tue	56	—	unknown	21:30–05:15 (marginal, 7.75 h)	87.2° 23:30	7.72	100%	53.5°
2047-09-04 Wed	58	—	unknown	21:30–05:15 (marginal, 7.75 h)	87.2° 23:25	7.77	100%	53.4°
2047-09-05 Thu	61	—	unknown	21:30–21:45 (good, 0.25 h)	87.2° 23:20	7.83	97%	55.2°
2047-09-06 Fri	67	—	unknown	21:25–22:50 (good, 1.42 h)	87.2° 23:20	7.88	93%	58.8°
2047-09-07 Sat	73	—	unknown	21:25–00:25 (good, 3.0 h)	87.2° 23:15	7.94	88%	63.6°
2047-09-08 Sun	79	—	unknown	21:20–02:25 (good, 5.08 h)	87.2° 23:10	7.99	81%	69.4°
2047-09-09 Mon	100	—	unknown	21:20–03:30 (good, 6.17 h)	87.2° 23:05	8.05	73%	75.9°
2047-09-10 Tue	100	—	unknown	21:20–04:40 (good, 7.33 h)	87.2° 23:05	8.1	64%	82.7°
2047-09-11 Wed	100	—	unknown	21:15–04:55 (good, 7.67 h)	87.2° 23:00	8.16	55%	89.8°
2047-09-12 Thu	100	—	unknown	21:15–05:00 (good, 7.75 h)	87.2° 22:55	8.21	46%	97.0°
2047-09-13 Fri	100	—	unknown	21:10–05:00 (good, 7.83 h)	87.2° 22:50	8.26	36%	104.2°
2047-09-14 Sat	100	—	unknown	21:10–05:00 (good, 7.83 h)	87.2° 22:45	8.32	27%	111.0°
2047-09-15 Sun	100	—	unknown	21:10–05:00 (good, 7.83 h)	87.2° 22:45	8.37	18%	117.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-08-17&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.