operation

    OpenVMS usage:function_code
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference

    The conversion to be performed. The operation argument is the
    address of an unsigned longword specifying the operation. Valid
    values for operation are the following:

    Operation              Interpretation

    LIB$K_DELTA_WEEKS_F    Fractional weeks
    LIB$K_DELTA_DAYS_F     Fractional days
    LIB$K_DELTA_HOURS_F    Fractional hours
    LIB$K_DELTA_MINUTES_F  Fractional minutes
    LIB$K_DELTA_SECONDS_F  Fractional seconds

 input-time

    OpenVMS usage:varying_arg
    type:         F_floating
    access:       read only
    mechanism:    by reference

    Delta time to be converted. The input-time argument is the
    address of this input time. The value you supply for input-time
    must be greater than 0.

 resultant-time

    OpenVMS usage:date_time
    type:         quadword (unsigned)
    access:       write only
    mechanism:    by reference

    The OpenVMS internal format delta time that results from the
    conversion. The resultant-time argument is the address of an
    unsigned quadword containing the result.