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: 10-21 (100), 10-22 (100), 10-23 (100), 10-24 (100), 10-25 (100) — by astronomy; check the weather when the night is within four days.

2043-10-16astronomy score per night — click a bar for that night2043-11-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-10-16 Fri	55	—	unknown	20:15–03:15 (marginal, 7.0 h)	87.2° 20:40	9.86	96%	60.0°
2043-10-17 Sat	56	—	unknown	20:10–20:25 (good, 0.25 h)	87.2° 20:35	9.9	100%	63.2°
2043-10-18 Sun	63	—	unknown	20:10–21:25 (good, 1.25 h)	87.2° 20:35	9.94	100%	68.2°
2043-10-19 Mon	72	—	unknown	20:10–23:15 (good, 3.08 h)	87.2° 20:30	9.99	97%	74.5°
2043-10-20 Tue	78	—	unknown	20:10–00:20 (good, 4.17 h)	87.2° 20:25	10.03	91%	81.7°
2043-10-21 Wed	100	—	unknown	20:05–01:35 (good, 5.5 h)	87.2° 20:20	10.07	84%	89.3°
2043-10-22 Thu	100	—	unknown	20:05–02:10 (good, 6.08 h)	87.2° 20:15	10.11	74%	96.8°
2043-10-23 Fri	100	—	unknown	20:05–02:15 (good, 6.17 h)	87.2° 20:15	10.15	63%	103.8°
2043-10-24 Sat	100	—	unknown	20:00–02:20 (good, 6.33 h)	87.2° 20:10	10.19	52%	110.0°
2043-10-25 Sun	100	—	unknown	19:00–01:20 (good, 6.33 h)	87.2° 19:05	10.23	41%	115.0°
2043-10-26 Mon	100	—	unknown	19:00–01:20 (good, 6.33 h)	87.2° 19:00	10.27	31%	118.6°
2043-10-27 Tue	100	—	unknown	19:00–01:20 (good, 6.33 h)	87.2° 19:00	10.31	22%	120.7°
2043-10-28 Wed	100	—	unknown	18:55–01:15 (good, 6.33 h)	87.2° 18:55	10.35	14%	121.0°
2043-10-29 Thu	100	—	unknown	18:55–01:10 (good, 6.25 h)	87.2° 18:50	10.39	8%	119.7°
2043-10-30 Fri	100	—	unknown	18:55–01:05 (good, 6.17 h)	87.2° 18:45	10.42	3%	116.9°
2043-10-31 Sat	100	—	unknown	18:55–01:00 (good, 6.08 h)	87.2° 18:40	10.46	1%	113.0°
2043-11-01 Sun	100	—	unknown	18:50–01:00 (good, 6.17 h)	87.2° 18:40	10.5	0%	108.1°
2043-11-02 Mon	100	—	unknown	18:50–00:55 (good, 6.08 h)	87.2° 18:35	10.53	1%	102.6°
2043-11-03 Tue	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.2° 18:30	10.57	4%	96.8°
2043-11-04 Wed	100	—	unknown	18:50–00:45 (good, 5.92 h)	87.2° 18:25	10.6	8%	90.7°
2043-11-05 Thu	100	—	unknown	18:50–00:40 (good, 5.83 h)	87.2° 18:20	10.64	14%	84.6°
2043-11-06 Fri	100	—	unknown	18:45–00:40 (good, 5.92 h)	87.2° 18:20	10.67	22%	78.7°
2043-11-07 Sat	100	—	unknown	18:45–00:35 (good, 5.83 h)	87.2° 18:15	10.71	30%	73.1°
2043-11-08 Sun	93	—	unknown	18:45–00:30 (good, 5.75 h)	87.2° 18:10	10.74	39%	68.0°
2043-11-09 Mon	85	—	unknown	18:45–00:25 (good, 5.67 h)	87.2° 18:05	10.77	49%	63.7°
2043-11-10 Tue	75	—	unknown	18:45–00:00 (good, 5.25 h)	87.2° 18:05	10.8	59%	60.6°
2043-11-11 Wed	67	—	unknown	18:45–23:10 (good, 4.42 h)	87.2° 18:00	10.84	69%	59.0°
2043-11-12 Thu	56	—	unknown	18:40–20:45 (good, 2.08 h)	87.2° 17:55	10.87	79%	59.2°
2043-11-13 Fri	48	—	unknown	18:40–00:30 (marginal, 5.83 h)	87.2° 17:50	10.9	87%	61.4°
2043-11-14 Sat	46	—	unknown	18:40–00:15 (marginal, 5.58 h)	87.2° 17:45	10.93	94%	65.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-10-16&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.