How To Calculating Years, Months, and Days Between Two Dates

MORE INFORMATION

DO BTWNDATE.PRG WITH startdate, enddate
				

DO BTWNDATE WITH {01/05/93},{01/05/95}
				

Code Sample

   *
   * BTWNDATE.PRG
   *

   PARAMETERS startdate, enddate
   IF startdate > enddate

        WAIT WINDOW "Start date must " + CHR(13) ;
        + "be earlier than End date"
        RETURN

   ENDIF
   IF PARAMETERS() <> 2

        WAIT WINDOW "Not Correct Number of Parameters"
        RETURN

   ENDIF

   PRIVATE  precmpdate, vyears, vmonths, vdays
   precmpdate={}
   vyears=0
   vmonths=0
   vdays=0
   
   * Calculate:
   *     endofmonth is the last day of month prior to month of enddate
   *
   
   endofmonth = CTOD(ALLTRIM(STR(MONTH(enddate))) + '/' + "01" + '/' + ;
   ALLTRIM(STR(YEAR(enddate)))) - 1
   *
   IF MONTH(startdate) <= MONTH(enddate)

        vyears = YEAR(enddate) - YEAR(startdate)
        IF DAY(startdate) <= DAY(enddate)
             vmonths = MONTH(enddate) - MONTH(startdate)
             vdays = DAY(enddate) - DAY(startdate)
        ELSE
             IF MONTH(startdate) = MONTH(enddate)
                  vyears = vyears - 1
             ENDIF
             vmonths = MOD(MONTH(enddate) - MONTH(startdate) - 1 + 12, 12)
             vdays = endofmonth - precmpdate + DAY(enddate)
        ENDIF

   ELSE

        vyears = YEAR(enddate) - YEAR(startdate) - 1
        IF DAY(startdate) > DAY(enddate)
             vmonths = MONTH(enddate) - MONTH(startdate) + 12 - 1
             vdays = endofmonth - precmpdate + DAY(enddate)
        ELSE
             vmonths = MONTH(enddate) - MONTH(startdate) + 12
             vdays = DAY(enddate) - DAY(startdate)
        ENDIF

   ENDIF
   CLEAR
   WAIT WINDOW  CHR(13) + ;
             '  Years: '  + STR(vyears) + CHR(13) + ;
             ' Months: ' + STR(vmonths) + CHR(13) + ;
             '   Days: ' + STR(vdays) + CHR(13) + ;
             CHR(13) + ;
             ' Between ' + DTOC(startdate) + CHR(13) +;
             '     and ' + DTOC(enddate)

   RETURN