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: 10-18 (100), 10-19 (100), 10-20 (100), 10-21 (100), 10-22 (100) — by astronomy; check the weather when the night is within four days.

2046-10-15astronomy score per night — click a bar for that night2046-11-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-10-15 Mon	62	—	unknown	20:15–21:25 (good, 1.17 h)	87.2° 20:45	9.83	99%	66.9°
2046-10-16 Tue	71	—	unknown	20:15–23:05 (good, 2.83 h)	87.2° 20:40	9.87	96%	73.0°
2046-10-17 Wed	77	—	unknown	20:10–00:15 (good, 4.08 h)	87.2° 20:35	9.91	92%	79.7°
2046-10-18 Thu	100	—	unknown	20:10–01:20 (good, 5.17 h)	87.2° 20:30	9.96	86%	86.7°
2046-10-19 Fri	100	—	unknown	20:10–02:15 (good, 6.08 h)	87.2° 20:30	10.0	78%	94.0°
2046-10-20 Sat	100	—	unknown	20:05–02:25 (good, 6.33 h)	87.2° 20:25	10.04	70%	101.3°
2046-10-21 Sun	100	—	unknown	20:05–02:30 (good, 6.42 h)	87.2° 20:20	10.08	60%	108.4°
2046-10-22 Mon	100	—	unknown	20:05–02:30 (good, 6.42 h)	87.2° 20:15	10.12	49%	114.8°
2046-10-23 Tue	100	—	unknown	20:05–02:30 (good, 6.42 h)	87.1° 20:10	10.16	38%	120.3°
2046-10-24 Wed	100	—	unknown	20:00–02:30 (good, 6.5 h)	87.2° 20:10	10.2	28%	124.2°
2046-10-25 Thu	100	—	unknown	20:00–02:25 (good, 6.42 h)	87.2° 20:05	10.24	18%	125.9°
2046-10-26 Fri	100	—	unknown	20:00–02:20 (good, 6.33 h)	87.2° 20:00	10.28	10%	124.9°
2046-10-27 Sat	100	—	unknown	20:00–02:15 (good, 6.25 h)	87.2° 19:55	10.32	4%	121.2°
2046-10-28 Sun	100	—	unknown	18:55–01:15 (good, 6.33 h)	87.1° 18:55	10.36	1%	115.4°
2046-10-29 Mon	100	—	unknown	18:55–01:10 (good, 6.25 h)	87.2° 18:50	10.4	0%	108.1°
2046-10-30 Tue	100	—	unknown	18:55–01:05 (good, 6.17 h)	87.2° 18:45	10.43	3%	99.9°
2046-10-31 Wed	100	—	unknown	18:55–01:00 (good, 6.08 h)	87.2° 18:40	10.47	8%	91.5°
2046-11-01 Thu	100	—	unknown	18:50–00:55 (good, 6.08 h)	87.2° 18:35	10.51	16%	83.3°
2046-11-02 Fri	100	—	unknown	18:50–00:55 (good, 6.08 h)	87.2° 18:35	10.54	25%	75.5°
2046-11-03 Sat	98	—	unknown	18:50–00:50 (good, 6.0 h)	87.2° 18:30	10.58	34%	68.6°
2046-11-04 Sun	90	—	unknown	18:50–00:45 (good, 5.92 h)	87.2° 18:25	10.61	44%	62.8°
2046-11-05 Mon	82	—	unknown	18:50–00:40 (good, 5.83 h)	87.2° 18:20	10.65	54%	58.3°
2046-11-06 Tue	70	—	unknown	18:45–00:10 (good, 5.42 h)	87.1° 18:15	10.68	63%	55.3°
2046-11-07 Wed	60	—	unknown	18:45–21:50 (good, 3.08 h)	87.2° 18:15	10.72	72%	54.0°
2046-11-08 Thu	50	—	unknown	18:45–00:55 (marginal, 6.17 h)	87.2° 18:10	10.75	80%	54.5°
2046-11-09 Fri	45	—	unknown	18:45–00:40 (marginal, 5.92 h)	87.2° 18:05	10.78	87%	56.8°
2046-11-10 Sat	43	—	unknown	18:45–00:30 (marginal, 5.75 h)	87.2° 18:00	10.81	93%	60.5°
2046-11-11 Sun	44	—	unknown	18:45–00:20 (marginal, 5.58 h)	87.1° 18:00	10.84	97%	65.4°
2046-11-12 Mon	51	—	unknown	18:40–19:30 (good, 0.83 h)	87.2° 17:55	10.87	99%	71.3°
2046-11-13 Tue	59	—	unknown	18:40–20:50 (good, 2.17 h)	87.2° 17:50	10.91	100%	78.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-10-15&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.