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 Vega: 11-13 (71), 11-14 (69), 11-15 (68), 11-16 (67), 11-17 (61) — by astronomy; check the weather when the night is within four days.

2031-11-13astronomy score per night — click a bar for that night2031-12-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-11-13 Thu	71	—	unknown	18:40–21:30 (good, 2.83 h)	87.1° 15:30	10.89	1%	79.9°
2031-11-14 Fri	69	—	unknown	18:40–21:25 (good, 2.75 h)	87.1° 15:25	10.92	0%	72.9°
2031-11-15 Sat	68	—	unknown	18:40–21:20 (good, 2.67 h)	87.1° 15:20	10.95	1%	66.6°
2031-11-16 Sun	67	—	unknown	18:40–21:15 (good, 2.58 h)	87.1° 15:15	10.98	6%	61.6°
2031-11-17 Mon	61	—	unknown	18:40–21:15 (good, 2.58 h)	87.1° 15:15	11.01	12%	58.3°
2031-11-18 Tue	54	—	unknown	18:40–21:10 (good, 2.5 h)	87.1° 15:10	11.04	21%	57.2°
2031-11-19 Wed	47	—	unknown	18:35–20:55 (good, 2.33 h)	87.1° 15:05	11.06	31%	58.5°
2031-11-20 Thu	41	—	unknown	18:35–20:45 (good, 2.17 h)	87.1° 15:00	11.09	42%	61.8°
2031-11-21 Fri	35	—	unknown	18:35–20:30 (good, 1.92 h)	87.1° 15:00	11.11	54%	66.8°
2031-11-22 Sat	30	—	unknown	18:35–20:00 (good, 1.42 h)	87.1° 14:55	11.14	64%	72.9°
2031-11-23 Sun	28	—	unknown	18:35–19:35 (good, 1.0 h)	87.1° 14:50	11.16	75%	79.8°
2031-11-24 Mon	28	—	unknown	18:35–19:30 (good, 0.92 h)	87.1° 14:45	11.19	83%	86.9°
2031-11-25 Tue	29	—	unknown	18:35–19:45 (good, 1.17 h)	87.1° 14:40	11.21	90%	94.0°
2031-11-26 Wed	31	—	unknown	18:35–20:05 (good, 1.5 h)	87.1° 14:40	11.23	96%	100.9°
2031-11-27 Thu	33	—	unknown	18:35–20:10 (good, 1.58 h)	87.1° 14:35	11.25	99%	107.3°
2031-11-28 Fri	35	—	unknown	18:35–20:10 (good, 1.58 h)	87.1° 14:30	11.27	100%	112.9°
2031-11-29 Sat	37	—	unknown	18:35–20:10 (good, 1.58 h)	87.1° 14:25	11.29	99%	117.5°
2031-11-30 Sun	38	—	unknown	18:35–20:10 (good, 1.58 h)	87.1° 14:20	11.31	96%	120.7°
2031-12-01 Mon	42	—	unknown	18:35–20:10 (good, 1.58 h)	87.1° 14:20	11.33	92%	122.5°
2031-12-02 Tue	42	—	unknown	18:35–20:15 (good, 1.67 h)	87.1° 14:15	11.34	86%	122.6°
2031-12-03 Wed	40	—	unknown	18:35–20:10 (good, 1.58 h)	87.1° 14:10	11.36	79%	121.2°
2031-12-04 Thu	39	—	unknown	18:35–20:05 (good, 1.5 h)	87.1° 14:05	11.38	70%	118.4°
2031-12-05 Fri	38	—	unknown	18:35–20:00 (good, 1.42 h)	87.1° 14:05	11.39	62%	114.4°
2031-12-06 Sat	36	—	unknown	18:35–20:00 (good, 1.42 h)	87.1° 14:00	11.4	52%	109.4°
2031-12-07 Sun	35	—	unknown	18:35–19:55 (good, 1.33 h)	87.1° 13:55	11.42	42%	103.5°
2031-12-08 Mon	33	—	unknown	18:35–19:50 (good, 1.25 h)	87.1° 13:50	11.43	33%	97.0°
2031-12-09 Tue	32	—	unknown	18:35–19:45 (good, 1.17 h)	87.1° 13:45	11.44	23%	90.1°
2031-12-10 Wed	31	—	unknown	18:35–19:40 (good, 1.08 h)	87.1° 13:45	11.45	15%	83.0°
2031-12-11 Thu	29	—	unknown	18:35–19:40 (good, 1.08 h)	87.1° 13:40	11.46	8%	75.9°
2031-12-12 Fri	28	—	unknown	18:35–19:35 (good, 1.0 h)	87.1° 13:35	11.47	3%	69.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-11-13&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.