前一天

前一天 means 'the day before' and is used to refer to the day preceding a specific date or event. It is commonly used in both formal and informal contexts to indicate a previous day.

The character 前 (qián) means 'before,' 一 (yī) means 'one,' and 天 (tiān) means 'day.' Together, they form a phrase that literally translates to 'the one day before,' which is a concise way to express the prior day.

前一天 is often used in daily conversation, such as when discussing past events, planning activities, or referring to previous days in a timeline. It is also used in writing, such as in journals, news articles, or historical records, to denote a sequence of events.