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: 10-20 (100), 10-21 (100), 10-22 (100), 10-23 (100), 10-24 (100) — by astronomy; check the weather when the night is within four days.

2038-10-20astronomy score per night — click a bar for that night2038-11-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-10-20 Wed	100	—	unknown	20:05–02:35 (good, 6.5 h)	87.3° 20:25	10.04	54%	110.1°
2038-10-21 Thu	100	—	unknown	20:05–02:35 (good, 6.5 h)	87.3° 20:20	10.08	44%	113.9°
2038-10-22 Fri	100	—	unknown	20:05–02:35 (good, 6.5 h)	87.3° 20:15	10.12	34%	116.7°
2038-10-23 Sat	100	—	unknown	20:05–02:30 (good, 6.42 h)	87.2° 20:10	10.16	24%	117.9°
2038-10-24 Sun	100	—	unknown	20:00–02:30 (good, 6.5 h)	87.3° 20:10	10.2	15%	117.5°
2038-10-25 Mon	100	—	unknown	20:00–02:25 (good, 6.42 h)	87.3° 20:05	10.24	8%	115.1°
2038-10-26 Tue	100	—	unknown	20:00–02:20 (good, 6.33 h)	87.3° 20:00	10.28	3%	111.0°
2038-10-27 Wed	100	—	unknown	20:00–02:15 (good, 6.25 h)	87.3° 19:55	10.32	0%	105.5°
2038-10-28 Thu	100	—	unknown	19:55–02:15 (good, 6.33 h)	87.3° 19:55	10.36	1%	99.0°
2038-10-29 Fri	100	—	unknown	19:55–02:10 (good, 6.25 h)	87.3° 19:50	10.39	5%	92.0°
2038-10-30 Sat	100	—	unknown	19:55–02:05 (good, 6.17 h)	87.3° 19:45	10.43	11%	85.0°
2038-10-31 Sun	100	—	unknown	18:55–01:00 (good, 6.08 h)	87.3° 18:40	10.47	20%	78.4°
2038-11-01 Mon	100	—	unknown	18:50–00:55 (good, 6.08 h)	87.3° 18:35	10.5	29%	72.7°
2038-11-02 Tue	95	—	unknown	18:50–00:55 (good, 6.08 h)	87.3° 18:35	10.54	40%	68.0°
2038-11-03 Wed	87	—	unknown	18:50–00:50 (good, 6.0 h)	87.3° 18:30	10.58	50%	64.6°
2038-11-04 Thu	80	—	unknown	18:50–00:45 (good, 5.92 h)	87.3° 18:25	10.61	60%	62.6°
2038-11-05 Fri	69	—	unknown	18:50–00:10 (good, 5.33 h)	87.3° 18:20	10.65	70%	62.1°
2038-11-06 Sat	66	—	unknown	18:45–22:15 (good, 3.5 h)	87.2° 18:15	10.68	79%	63.0°
2038-11-07 Sun	60	—	unknown	18:45–21:05 (good, 2.33 h)	87.3° 18:15	10.71	86%	65.1°
2038-11-08 Mon	57	—	unknown	18:45–20:10 (good, 1.42 h)	87.3° 18:10	10.75	92%	68.4°
2038-11-09 Tue	58	—	unknown	18:45–20:30 (good, 1.75 h)	87.3° 18:05	10.78	96%	72.5°
2038-11-10 Wed	61	—	unknown	18:45–21:00 (good, 2.25 h)	87.3° 18:00	10.81	99%	77.2°
2038-11-11 Thu	68	—	unknown	18:45–21:30 (good, 2.75 h)	87.3° 18:00	10.84	100%	82.4°
2038-11-12 Fri	77	—	unknown	18:40–22:05 (good, 3.42 h)	87.3° 17:55	10.87	99%	87.8°
2038-11-13 Sat	82	—	unknown	18:40–22:50 (good, 4.17 h)	87.3° 17:50	10.9	96%	93.4°
2038-11-14 Sun	100	—	unknown	18:40–23:30 (good, 4.83 h)	87.3° 17:45	10.93	92%	98.9°
2038-11-15 Mon	100	—	unknown	18:40–23:40 (good, 5.0 h)	87.3° 17:40	10.96	86%	104.1°
2038-11-16 Tue	100	—	unknown	18:40–23:40 (good, 5.0 h)	87.3° 17:40	10.99	79%	108.8°
2038-11-17 Wed	100	—	unknown	18:40–23:40 (good, 5.0 h)	87.3° 17:35	11.02	70%	112.8°
2038-11-18 Thu	100	—	unknown	18:40–23:45 (good, 5.08 h)	87.3° 17:30	11.04	60%	115.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-10-20&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.