HoursBetween returns the number of hours between two specified TDateTime values.

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

For example, HoursBetween reports the difference between 10:00 A.M. and 10:59:59 A.M. on the same day as zero (0) hours between, because the hour stops a second short of an entire hour.

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

Declaration: Function HoursBetween(const ANow, AThen: TDateTime): Int64;

A simple example follows.

procedure OnMapEvent(var Value:Variant);
var
TheDate, ThatDate : TDateTime;
NumBetw : integer;
begin
//Result is 0 hours
TheDate := EncodeDateTime(2023, 02, 13, 10, 00, 00, 000);
ThatDate := EncodeDateTime(2023, 02, 13, 10, 59, 59, 000);
NumBetw := HoursBetween(TheDate,ThatDate);
LogInfo('The number of hours between these dates is - '+IntToStr(NumBetw));
 
//Result is 1 hour
ThatDate := EncodeDateTime(2023, 02, 13, 11, 00, 00, 000);
NumBetw := HoursBetween(TheDate,ThatDate);
LogInfo('The number of hours between these dates is - '+IntToStr(NumBetw));
 
end;