--- C:/Program Files (x86)/Embarcadero/RAD Studio/7.0/lib/jvcl/run/JvDateTimePicker.pas	Чт ноя 10 15:47:26 2011
+++ C:/Users/hohlovm/Documents/RAD Studio/Projects/JVDBDateTimePicker/JvDateTimePicker.pas	Чт мар 29 11:00:48 2012
@@ -152,10 +152,8 @@
 end;
 
 function TJvDateTimePicker.WithinDelta(Val1, Val2: TDateTime): Boolean;
-const
-  cOneSecond = 1 / 86400;
 begin
-  Result := Abs(Frac(Val1) - Frac(Val2)) <= cOneSecond;
+  Result := Abs(Frac(Val1) - Frac(Val2)) < EncodeTime(0, 0, 1, 0);
 end;
 
 function TJvDateTimePicker.CheckNullValue: Boolean;