/deɪ ˈsɜrtən/ – Phrase
Definition: ngày cụ thể, ngày nhất định, ngày đã định.
A more thorough explanation: “Day certain” refers to a specific date or day that is fixed and known with certainty. In legal terms, it is often used to indicate a deadline or a specific date by which an action must be taken or an event must occur.
Example: The court has set a day certain for the hearing of the case, which is scheduled for next Monday.