Delphi Basics : DaySpan command

DelphiBasics

DaySpan
Function

Gives the fractional number of days between 2 dates

DateUtils unit

function DaySpan(const ToDate, FromDate TDateTime):Double;

Description

The DaySpan function subtracts the FromDate from the ToDate, returning the fractional days difference.

The Double return value contains the number of days as the integral part, and the part-day remainder as the fractional part.

For example, a difference of 2 days and 6 hours would give a value of 2.25

Related commands

DaysBetween		Gives the whole number of days between 2 dates
DaysInAMonth		Gives the number of days in a month
DaysInAYear		Gives the number of days in a year

Download this web site as a Windows program.

Example code : Find the days difference between two date+time values.

var
  fromdate, toDate : TDateTime;

begin
  // Set up our date variables
  fromDate := EncodeDateTime(2000, 01, 01, 0, 0, 0, 0);
  toDate   := EncodeDateTime(2000, 01, 02, 12, 0, 0, 0);

  // Display these dates and the days between them
  ShowMessage('From date = '+DateTimeToStr(fromDate));
  ShowMessage('To   date = '+DateTimeToStr(toDate));
  ShowMessage('Fractional days difference = '+
              FloatToStr(DaySpan(toDate, fromDate))+' days');
end;

Show full unit code

  From date = 01/01/2000
  To date = 02/01/2000 12:00:00
  Fractional days difference = 1.5 days