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: 07-31 (100), 08-01 (100), 08-02 (100), 08-03 (100), 08-04 (100) — by astronomy; check the weather when the night is within four days.

2038-07-31astronomy score per night — click a bar for that night2038-08-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-07-31 Sat	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.3° 01:45	5.8	0%	115.0°
2038-08-01 Sun	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.3° 01:40	5.85	1%	117.4°
2038-08-02 Mon	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.3° 01:35	5.91	5%	118.2°
2038-08-03 Tue	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.3° 01:30	5.96	11%	117.2°
2038-08-04 Wed	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.3° 01:25	6.02	19%	114.4°
2038-08-05 Thu	100	—	unknown	22:25–04:30 (good, 6.08 h)	87.3° 01:25	6.08	29%	110.1°
2038-08-06 Fri	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.3° 01:20	6.13	40%	104.6°
2038-08-07 Sat	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.3° 01:15	6.19	51%	98.4°
2038-08-08 Sun	100	—	unknown	22:20–04:35 (good, 6.25 h)	87.3° 01:10	6.25	62%	91.9°
2038-08-09 Mon	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.3° 01:05	6.3	73%	85.3°
2038-08-10 Tue	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.3° 01:05	6.36	82%	78.9°
2038-08-11 Wed	100	—	unknown	22:15–04:40 (good, 6.42 h)	87.3° 01:00	6.42	90%	73.2°
2038-08-12 Thu	95	—	unknown	22:15–04:45 (good, 6.5 h)	87.3° 00:55	6.47	95%	68.4°
2038-08-13 Fri	65	—	unknown	22:15–04:45 (good, 6.5 h)	87.3° 00:50	6.53	99%	64.7°
2038-08-14 Sat	64	—	unknown	22:10–23:35 (good, 1.42 h)	87.2° 00:50	6.59	100%	62.5°
2038-08-15 Sun	66	—	unknown	22:10–23:50 (good, 1.67 h)	87.3° 00:45	6.65	99%	61.7°
2038-08-16 Mon	70	—	unknown	22:05–00:35 (good, 2.5 h)	87.3° 00:40	6.7	96%	62.5°
2038-08-17 Tue	74	—	unknown	22:05–01:50 (good, 3.75 h)	87.3° 00:35	6.76	91%	64.6°
2038-08-18 Wed	100	—	unknown	22:05–03:35 (good, 5.5 h)	87.3° 00:30	6.82	85%	67.8°
2038-08-19 Thu	100	—	unknown	22:00–04:25 (good, 6.42 h)	87.3° 00:30	6.88	77%	72.0°
2038-08-20 Fri	100	—	unknown	22:00–04:55 (good, 6.92 h)	87.3° 00:25	6.94	69%	76.7°
2038-08-21 Sat	100	—	unknown	21:55–04:55 (good, 7.0 h)	87.3° 00:20	6.99	60%	82.0°
2038-08-22 Sun	100	—	unknown	21:55–05:00 (good, 7.08 h)	87.3° 00:15	7.05	50%	87.5°
2038-08-23 Mon	100	—	unknown	21:55–05:00 (good, 7.08 h)	87.3° 00:10	7.11	41%	93.2°
2038-08-24 Tue	100	—	unknown	21:50–05:00 (good, 7.17 h)	87.3° 00:10	7.16	31%	98.8°
2038-08-25 Wed	100	—	unknown	21:50–05:00 (good, 7.17 h)	87.3° 00:05	7.22	22%	104.3°
2038-08-26 Thu	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.3° 00:00	7.28	14%	109.3°
2038-08-27 Fri	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.3° 23:55	7.33	8%	113.6°
2038-08-28 Sat	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.2° 23:55	7.39	3%	116.6°
2038-08-29 Sun	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.3° 23:50	7.45	0%	118.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-07-31&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.