The DayOf function returns the day number of the month represented by the given date value. The resulting day number is a number between 1 and 31.

Declaration: Function DayOf( const AValue : TDateTime) : Word;

Function DayOfTheMonth(const AValue: TDateTime): Word;

An example follows.

procedure OnMapEvent(var Value:Variant);
var
TheDay, TheMthDay : word;
begin
//If the date is 2023-11-30 then the result is 30
TheDay := DayOf(Date);
LogInfo('The DAYOF is '+IntToStr(TheDay));
 
//If the date is 2023-11-29 then the result is 29
TheMthDay := DayOfTheMonth(Yesterday);
LogInfo('The DAYOFTHEMONTH is '+IntToStr(TheMthDay));
end;

DayOf has the same functionality as the DayOfTheMonth function.