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: 12-17 (78), 12-18 (67), 12-30 (56), 12-19 (55), 12-31 (55) — by astronomy; check the weather when the night is within four days.

2031-12-17astronomy score per night — click a bar for that night2032-01-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-12-17 Wed	78	—	unknown	18:35–21:55 (good, 3.33 h)	87.2° 15:35	11.5	18%	55.7°
2031-12-18 Thu	67	—	unknown	18:35–21:45 (good, 3.17 h)	87.2° 15:35	11.5	27%	53.0°
2031-12-19 Fri	55	—	unknown	18:35–21:30 (good, 2.92 h)	87.2° 15:30	11.51	38%	53.0°
2031-12-20 Sat	45	—	unknown	18:35–21:15 (good, 2.67 h)	87.2° 15:25	11.51	49%	55.5°
2031-12-21 Sun	37	—	unknown	18:35–20:00 (good, 1.42 h)	87.2° 15:20	11.51	60%	60.0°
2031-12-22 Mon	33	—	unknown	18:35–19:10 (good, 0.58 h)	87.2° 15:15	11.51	70%	65.9°
2031-12-23 Tue	30	—	unknown	18:40–18:55 (good, 0.25 h)	87.2° 15:15	11.51	79%	72.6°
2031-12-24 Wed	31	—	unknown	18:40–19:05 (good, 0.42 h)	87.2° 15:10	11.5	87%	79.9°
2031-12-25 Thu	33	—	unknown	18:40–19:35 (good, 0.92 h)	87.2° 15:05	11.5	93%	87.4°
2031-12-26 Fri	36	—	unknown	18:40–20:10 (good, 1.5 h)	87.2° 15:00	11.5	97%	94.9°
2031-12-27 Sat	41	—	unknown	18:40–20:45 (good, 2.08 h)	87.2° 15:00	11.49	99%	102.1°
2031-12-28 Sun	45	—	unknown	18:40–20:50 (good, 2.17 h)	87.2° 14:55	11.49	100%	108.9°
2031-12-29 Mon	49	—	unknown	18:40–20:55 (good, 2.25 h)	87.2° 14:50	11.48	98%	115.1°
2031-12-30 Tue	56	—	unknown	18:40–20:55 (good, 2.25 h)	87.2° 14:45	11.47	96%	120.2°
2031-12-31 Wed	55	—	unknown	18:45–20:55 (good, 2.17 h)	87.2° 14:40	11.46	91%	124.2°
2032-01-01 Thu	55	—	unknown	18:45–20:55 (good, 2.17 h)	87.2° 14:40	11.45	85%	126.6°
2032-01-02 Fri	54	—	unknown	18:45–20:55 (good, 2.17 h)	87.2° 14:35	11.44	77%	127.2°
2032-01-03 Sat	52	—	unknown	18:45–20:50 (good, 2.08 h)	87.2° 14:30	11.43	69%	126.0°
2032-01-04 Sun	50	—	unknown	18:45–20:45 (good, 2.0 h)	87.2° 14:25	11.42	60%	123.0°
2032-01-05 Mon	48	—	unknown	18:45–20:40 (good, 1.92 h)	87.2° 14:20	11.41	50%	118.3°
2032-01-06 Tue	47	—	unknown	18:45–20:40 (good, 1.92 h)	87.2° 14:20	11.39	40%	112.3°
2032-01-07 Wed	44	—	unknown	18:50–20:35 (good, 1.75 h)	87.2° 14:15	11.38	30%	105.2°
2032-01-08 Thu	43	—	unknown	18:50–20:30 (good, 1.67 h)	87.2° 14:10	11.36	20%	97.2°
2032-01-09 Fri	41	—	unknown	18:50–20:25 (good, 1.58 h)	87.2° 14:05	11.35	12%	88.7°
2032-01-10 Sat	40	—	unknown	18:50–20:25 (good, 1.58 h)	87.2° 14:05	11.33	5%	79.9°
2032-01-11 Sun	38	—	unknown	18:50–20:20 (good, 1.5 h)	87.2° 14:00	11.31	1%	71.4°
2032-01-12 Mon	35	—	unknown	18:55–20:15 (good, 1.33 h)	87.2° 13:55	11.3	0%	63.8°
2032-01-13 Tue	34	—	unknown	18:55–20:10 (good, 1.25 h)	87.2° 13:50	11.28	2%	57.7°
2032-01-14 Wed	31	—	unknown	18:55–20:05 (good, 1.17 h)	87.2° 13:45	11.26	7%	53.8°
2032-01-15 Thu	28	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:45	11.23	14%	52.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-12-17&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.