also: だいあん
noun
auspicious day; day of great luck
In the traditional six-day calendar (六曜), 大安 is considered the luckiest day, suitable for weddings, openings, and celebrations.
See also: 六曜
結婚式は大安の日を選びました。
We chose a day of great luck for the wedding.
大安吉日
Many couples register their marriage on an auspicious day.
From Chinese-derived terms 大 (great) and 安 (peace/calm), referring to a day of great peace and fortune in the traditional almanac.