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: 12-24 (70), 12-23 (69), 12-25 (69), 12-22 (68), 12-26 (67) — by astronomy; check the weather when the night is within four days.

2029-12-17astronomy score per night — click a bar for that night2030-01-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-12-17 Mon	35	—	unknown	18:35–19:05 (good, 0.5 h)	87.2° 15:35	11.5	92%	78.8°
2029-12-18 Tue	38	—	unknown	18:35–19:40 (good, 1.08 h)	87.2° 15:30	11.5	96%	85.9°
2029-12-19 Wed	43	—	unknown	18:35–20:20 (good, 1.75 h)	87.2° 15:25	11.51	99%	93.3°
2029-12-20 Thu	50	—	unknown	18:35–21:05 (good, 2.5 h)	87.2° 15:25	11.51	100%	100.7°
2029-12-21 Fri	55	—	unknown	18:35–21:15 (good, 2.67 h)	87.2° 15:20	11.51	99%	107.8°
2029-12-22 Sat	68	—	unknown	18:35–21:20 (good, 2.75 h)	87.2° 15:15	11.51	96%	114.5°
2029-12-23 Sun	69	—	unknown	18:40–21:20 (good, 2.67 h)	87.2° 15:10	11.51	91%	120.2°
2029-12-24 Mon	70	—	unknown	18:40–21:20 (good, 2.67 h)	87.2° 15:10	11.5	84%	124.6°
2029-12-25 Tue	69	—	unknown	18:40–21:25 (good, 2.75 h)	87.2° 15:05	11.5	76%	127.1°
2029-12-26 Wed	67	—	unknown	18:40–21:20 (good, 2.67 h)	87.2° 15:00	11.49	66%	127.4°
2029-12-27 Thu	65	—	unknown	18:40–21:15 (good, 2.58 h)	87.2° 14:55	11.49	55%	125.3°
2029-12-28 Fri	63	—	unknown	18:40–21:10 (good, 2.5 h)	87.2° 14:50	11.48	44%	120.9°
2029-12-29 Sat	61	—	unknown	18:40–21:10 (good, 2.5 h)	87.2° 14:50	11.48	33%	114.6°
2029-12-30 Sun	59	—	unknown	18:40–21:05 (good, 2.42 h)	87.2° 14:45	11.47	23%	107.0°
2029-12-31 Mon	56	—	unknown	18:45–21:00 (good, 2.25 h)	87.2° 14:40	11.46	14%	98.5°
2030-01-01 Tue	55	—	unknown	18:45–20:55 (good, 2.17 h)	87.2° 14:35	11.45	6%	89.6°
2030-01-02 Wed	53	—	unknown	18:45–20:50 (good, 2.08 h)	87.2° 14:30	11.44	2%	80.8°
2030-01-03 Thu	52	—	unknown	18:45–20:50 (good, 2.08 h)	87.2° 14:30	11.43	0%	72.4°
2030-01-04 Fri	50	—	unknown	18:45–20:45 (good, 2.0 h)	87.2° 14:25	11.42	1%	64.9°
2030-01-05 Sat	47	—	unknown	18:45–20:40 (good, 1.92 h)	87.2° 14:20	11.4	4%	58.8°
2030-01-06 Sun	42	—	unknown	18:50–20:35 (good, 1.75 h)	87.2° 14:15	11.39	10%	54.6°
2030-01-07 Mon	38	—	unknown	18:50–20:25 (good, 1.58 h)	87.2° 14:10	11.37	17%	52.6°
2030-01-08 Tue	33	—	unknown	18:50–20:15 (good, 1.42 h)	87.2° 14:10	11.36	25%	52.8°
2030-01-09 Wed	28	—	unknown	18:50–20:05 (good, 1.25 h)	87.2° 14:05	11.34	34%	55.0°
2030-01-10 Thu	23	—	unknown	18:50–19:50 (good, 1.0 h)	87.2° 14:00	11.32	44%	58.9°
2030-01-11 Fri	19	—	unknown	18:50–19:15 (good, 0.42 h)	87.2° 13:55	11.3	53%	64.0°
2030-01-12 Sat	17	—	unknown	18:55–20:45 (marginal, 1.83 h)	87.2° 13:55	11.29	63%	70.0°
2030-01-13 Sun	16	—	unknown	18:55–20:35 (marginal, 1.67 h)	87.2° 13:50	11.27	71%	76.7°
2030-01-14 Mon	15	—	unknown	18:55–20:30 (marginal, 1.58 h)	87.2° 13:45	11.25	80%	83.7°
2030-01-15 Tue	15	—	unknown	18:55–20:30 (marginal, 1.58 h)	87.2° 13:40	11.22	87%	91.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-12-17&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.