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 North America Nebula: 10-17 (100), 10-18 (100), 10-19 (100), 10-20 (100), 10-21 (100) — by astronomy; check the weather when the night is within four days.

2047-10-17astronomy score per night — click a bar for that night2047-11-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-10-17 Thu	100	—	unknown	20:10–02:55 (good, 6.75 h)	87.2° 20:35	9.9	2%	123.2°
2047-10-18 Fri	100	—	unknown	20:10–02:55 (good, 6.75 h)	87.2° 20:35	9.95	0%	117.7°
2047-10-19 Sat	100	—	unknown	20:10–02:50 (good, 6.67 h)	87.2° 20:30	9.99	1%	110.4°
2047-10-20 Sun	100	—	unknown	20:10–02:45 (good, 6.58 h)	87.2° 20:25	10.03	5%	102.1°
2047-10-21 Mon	100	—	unknown	20:05–02:40 (good, 6.58 h)	87.2° 20:20	10.07	11%	93.2°
2047-10-22 Tue	100	—	unknown	20:05–02:40 (good, 6.58 h)	87.1° 20:15	10.11	20%	84.4°
2047-10-23 Wed	100	—	unknown	20:05–02:35 (good, 6.5 h)	87.2° 20:15	10.15	30%	76.0°
2047-10-24 Thu	98	—	unknown	20:00–02:30 (good, 6.5 h)	87.2° 20:10	10.19	40%	68.5°
2047-10-25 Fri	90	—	unknown	20:00–02:25 (good, 6.42 h)	87.2° 20:05	10.23	51%	62.1°
2047-10-26 Sat	82	—	unknown	20:00–02:20 (good, 6.33 h)	87.2° 20:00	10.27	62%	57.2°
2047-10-27 Sun	65	—	unknown	19:00–00:30 (good, 5.5 h)	87.1° 19:00	10.31	71%	54.1°
2047-10-28 Mon	57	—	unknown	18:55–01:45 (marginal, 6.83 h)	87.2° 18:55	10.35	80%	53.0°
2047-10-29 Tue	48	—	unknown	18:55–01:30 (marginal, 6.58 h)	87.2° 18:50	10.39	87%	53.9°
2047-10-30 Wed	45	—	unknown	18:55–01:15 (marginal, 6.33 h)	87.2° 18:45	10.42	93%	56.6°
2047-10-31 Thu	45	—	unknown	18:55–01:05 (marginal, 6.17 h)	87.2° 18:40	10.46	97%	60.9°
2047-11-01 Fri	51	—	unknown	18:50–19:05 (good, 0.25 h)	87.2° 18:40	10.5	99%	66.2°
2047-11-02 Sat	59	—	unknown	18:50–20:20 (good, 1.5 h)	87.2° 18:35	10.53	100%	72.4°
2047-11-03 Sun	70	—	unknown	18:50–21:45 (good, 2.92 h)	87.2° 18:30	10.57	99%	79.1°
2047-11-04 Mon	78	—	unknown	18:50–22:40 (good, 3.83 h)	87.2° 18:25	10.61	96%	86.1°
2047-11-05 Tue	84	—	unknown	18:50–23:35 (good, 4.75 h)	87.1° 18:20	10.64	91%	93.2°
2047-11-06 Wed	100	—	unknown	18:45–00:10 (good, 5.42 h)	87.2° 18:20	10.67	85%	100.3°
2047-11-07 Thu	100	—	unknown	18:45–00:15 (good, 5.5 h)	87.2° 18:15	10.71	77%	107.2°
2047-11-08 Fri	100	—	unknown	18:45–00:20 (good, 5.58 h)	87.2° 18:10	10.74	69%	113.6°
2047-11-09 Sat	100	—	unknown	18:45–00:20 (good, 5.58 h)	87.2° 18:05	10.77	59%	119.3°
2047-11-10 Sun	100	—	unknown	18:45–00:20 (good, 5.58 h)	87.1° 18:05	10.81	49%	123.7°
2047-11-11 Mon	100	—	unknown	18:45–00:20 (good, 5.58 h)	87.2° 18:00	10.84	38%	126.5°
2047-11-12 Tue	100	—	unknown	18:40–00:15 (good, 5.58 h)	87.2° 17:55	10.87	28%	127.0°
2047-11-13 Wed	100	—	unknown	18:40–00:10 (good, 5.5 h)	87.2° 17:50	10.9	18%	125.0°
2047-11-14 Thu	100	—	unknown	18:40–00:05 (good, 5.42 h)	87.2° 17:45	10.93	10%	120.6°
2047-11-15 Fri	100	—	unknown	18:40–00:05 (good, 5.42 h)	87.1° 17:45	10.96	4%	114.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-10-17&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.