Date/time expressions with different interval leading digits
  precision are not comparable

  Explanation:  You attempted to compare or perform an arithmetic
  operation on two date/time expressions with different interval
  leading digits precisions.  These expressions are considered not
  comparable, and therefore this operation is not allowed.

  User Action:  Use different operands or use the CAST function to
  change the interval leading digits precision of one of the
  operands.