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: 12-19 (84), 12-20 (82), 12-21 (78), 12-22 (76), 12-23 (74) — by astronomy; check the weather when the night is within four days.

2046-12-19astronomy score per night — click a bar for that night2047-01-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-12-19 Wed	84	—	unknown	18:35–21:50 (good, 3.25 h)	87.2° 15:30	11.51	58%	126.2°
2046-12-20 Thu	82	—	unknown	18:35–21:45 (good, 3.17 h)	87.2° 15:25	11.51	46%	124.1°
2046-12-21 Fri	78	—	unknown	18:35–21:40 (good, 3.08 h)	87.2° 15:20	11.51	35%	119.8°
2046-12-22 Sat	76	—	unknown	18:35–21:35 (good, 3.0 h)	87.2° 15:15	11.51	25%	113.7°
2046-12-23 Sun	74	—	unknown	18:40–21:35 (good, 2.92 h)	87.1° 15:15	11.51	15%	106.4°
2046-12-24 Mon	72	—	unknown	18:40–21:30 (good, 2.83 h)	87.2° 15:10	11.5	8%	98.4°
2046-12-25 Tue	70	—	unknown	18:40–21:25 (good, 2.75 h)	87.2° 15:05	11.5	3%	90.0°
2046-12-26 Wed	68	—	unknown	18:40–21:20 (good, 2.67 h)	87.2° 15:00	11.5	0%	81.8°
2046-12-27 Thu	66	—	unknown	18:40–21:15 (good, 2.58 h)	87.2° 14:55	11.49	0%	74.0°
2046-12-28 Fri	65	—	unknown	18:40–21:15 (good, 2.58 h)	87.2° 14:55	11.48	3%	67.0°
2046-12-29 Sat	60	—	unknown	18:40–21:10 (good, 2.5 h)	87.2° 14:50	11.48	7%	61.2°
2046-12-30 Sun	55	—	unknown	18:40–21:05 (good, 2.42 h)	87.2° 14:45	11.47	13%	56.9°
2046-12-31 Mon	47	—	unknown	18:45–20:55 (good, 2.17 h)	87.2° 14:40	11.46	20%	54.3°
2047-01-01 Tue	41	—	unknown	18:45–20:45 (good, 2.0 h)	87.2° 14:35	11.45	29%	53.7°
2047-01-02 Wed	35	—	unknown	18:45–20:30 (good, 1.75 h)	87.2° 14:35	11.44	38%	54.8°
2047-01-03 Thu	29	—	unknown	18:45–20:20 (good, 1.58 h)	87.2° 14:30	11.43	47%	57.7°
2047-01-04 Fri	25	—	unknown	18:45–19:20 (good, 0.58 h)	87.2° 14:25	11.42	57%	61.9°
2047-01-05 Sat	21	—	unknown	18:45–21:10 (marginal, 2.42 h)	87.2° 14:20	11.4	66%	67.3°
2047-01-06 Sun	19	—	unknown	18:50–21:00 (marginal, 2.17 h)	87.1° 14:15	11.39	75%	73.5°
2047-01-07 Mon	19	—	unknown	18:50–20:55 (marginal, 2.08 h)	87.2° 14:15	11.37	83%	80.3°
2047-01-08 Tue	20	—	unknown	18:15–20:55 (marginal, 2.67 h)	87.2° 14:10	11.36	90%	87.6°
2047-01-09 Wed	22	—	unknown	18:50–19:20 (good, 0.5 h)	87.2° 14:05	11.34	95%	95.2°
2047-01-10 Thu	23	—	unknown	18:50–19:50 (good, 1.0 h)	87.2° 14:00	11.33	98%	102.8°
2047-01-11 Fri	26	—	unknown	18:50–19:55 (good, 1.08 h)	87.2° 14:00	11.31	100%	110.1°
2047-01-12 Sat	28	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:55	11.29	99%	116.6°
2047-01-13 Sun	32	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:50	11.27	96%	121.9°
2047-01-14 Mon	32	—	unknown	18:55–20:05 (good, 1.17 h)	87.2° 13:45	11.25	90%	125.3°
2047-01-15 Tue	30	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:40	11.23	82%	126.3°
2047-01-16 Wed	29	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:40	11.21	72%	124.8°
2047-01-17 Thu	27	—	unknown	19:00–19:55 (good, 0.92 h)	87.2° 13:35	11.18	61%	121.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-12-19&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.