SysUtils

FormatDateTime formats the TDateTime value given by DateTime using the format given by Format. See the table below for information about the supported format strings. 

If the string specified by the Format parameter is empty, the TDateTime value is formatted as if a 'c' format specifier had been given. 

The first form of FormatDateTime is not thread-safe, because it uses localization information contained in global variables. The second form of FormatDateTime, which is thread-safe, refers to localization information contained in the FormatSettings parameter. Before calling the thread-safe form of FormatDateTime, you must populate FormatSettings with localization information. To populate FormatSettings with a set of default locale values, call GetLocaleFormatSettings. 

Date Time Format Strings are composed from specifiers that represent values to be inserted into the formatted string. Some specifiers (such as "d"), simply format numbers or strings. Other specifiers (such as "/") refer to locale-specific strings from global variables. 

In the following table, specifiers are given in lower case. Case is ignored in formats, except for the "am/pm" and "a/p" specifiers.

C++ Examples: 

/*
The following example uses FormatDateTime to set the string
variable S to a sentence indicating a meeting time in 3
hours. The sentence has the form "The meeting is on
Wednesday, February 15, 1995 at 2:30 PM."
*/
void __fastcall TForm1::Button1Click(TObject *Sender)
{
  AnsiString S = "The meeting is on ";
  S = S + FormatDateTime("dddd, mmmm d, yyyy ' at ' hh:mm AM/PM", IncHour(Now(), 3));
  Label1->Caption = S;
}

Delphi Examples: 

{
The following example uses FormatDateTime to set the string
variable S to a sentence indicating a meeting time in 3
hours. The sentence has the form "The meeting is on
Wednesday, February 15, 2008 at 2:30 PM."
}
procedure TForm1.Button1Click(Sender: TObject);
var S : string;
begin
  S := SysUtils.FormatDateTime(
    '"The meeting is on " dddd, mmmm d, yyyy, " at " hh:mm AM/PM', IncHour(Now(), 3));
  Label1.Caption := S;
end;