WeeksBetween returns the approximate number of weeks between two specified TDateTime values.

Fractional weeks are not counted, so the function will return a whole integer value only.

For example, WeeksBetween reports the difference between 12:00 A.M. on 13th February and 11:59 P.M. on 19th February as zero(0), because it is one (1) minute short of a full week.

The ordering of the two dates doesn't matter - the number of weeks will not be negative.

Declaration: Function WeeksBetween(const ANow, AThen: TDateTime): Integer;

Examples follow.

procedure OnMapEvent(var Value:Variant);
var
TheDate, ThatDate : TDateTime;
NumBetw : integer;
begin
//Result is zero (as above)
TheDate := EncodeDateTime(2023, 02, 13, 00, 00, 00, 000);
ThatDate := EncodeDateTime(2023, 02, 19, 23, 59, 00, 000);
NumBetw := WeeksBetween(TheDate,ThatDate);
LogInfo('The number of weeks between these dates is - '+IntToStr(NumBetw));
 
//Result is 1
ThatDate := EncodeDateTime(2023, 02, 20, 00, 00, 00, 000);
NumBetw := WeeksBetween(TheDate,ThatDate);
LogInfo('The number of weeks between these dates is - '+IntToStr(NumBetw));
end;