این کد اختلاف زمان بین دو ساعت را بر می گرداند:

FUNCTION TimeDif
PARAMETERS tDateTime1, tDateTime2

LOCAL lReturn, myHours, myMinutes, mySeconds
lReturn = .t.

IF PARAMETERS() # 2
lReturn = .f.
ENDIF
IF ! VARTYPE(tDateTime1) = "T"
lReturn = .f.
ENDIF
IF ! VARTYPE(tDateTime2) = "T"
lReturn = .f.
ENDIF
IF lReturn
IF tDateTime2 > tDateTime1
mySeconds = tdateTime2 - tDateTime1
ELSE
mySeconds = tdateTime1 - tDateTime2
ENDIF
mySeconds=INT(mySeconds)
cTime = TRANSFORM(INT(mySeconds/3600),"9999")+":"+ ;
TRANSFORM(MOD(INT(mySeconds/60),60),"99")+":"+ ;
TRANSFORM(MOD(mySeconds,60),"99")
WAIT WINDOW "Time Difference = "+cTime
RETURN cTime
ELSE
=MESSAGEBOX("Pass to this function ;
From DateTime and To DateTime", ;
0+16,"Wrong Parameters")
RETURN lReturn
ENDIF