If your purpose for conversion is to compare dates try this
x = datevalue(somedate$)
y = datevalue(somotherdate$)
then simply compare x and y with < > and =
you can use date formats of
"01/01/05"
"01/01/2005"
"Jan 1, 2005"
"January 1, 2005"
or you can add and subtract days to determine other dates
x = datevalue(todaysdate$)+7
now x = one week from today
hope this helps