Bad conversion from EndOfTheMonth(date) to Variant value

Question

I have a TDateTime value (that I get as result from EndOfTheMonth(date)) to a variant type. The result is wrongly rounded. Let's have a look at example:

  data := EndOfTheMonth(date);
  V := data;
  ShowMessage(DateTimeToStr(data) + ' vs ' + VarToStr(V));
 // output is
 // data = 2012-01-31 23:59:59
 // v    = 2012-02-01            // why next day?

Is it designed behaviour? How to work around this?

Answer 1

ShowMessage(DateTimeToStr(data) + ' vs ' + DateTimeToStr(VarToDateTime(V)));

Update: I would guess the problem is that the last millisecond of the month is very close to 0:00:00 the next day, that is, the TDateTime value (which is basically a double) is very close to an integer (e.g. 41029.9999999884 is very close to 41029) and so the VarToStr function assumes the decimals to be numerical fuzz.