The value of this object specifies how long this row can
exist in the smRunTable after the script has terminated.
This object returns the remaining time that the row may
exist before it is aged out. The object is initialized with
the value of the associated smLaunchExpireTime object and
ticks backwards. The entry in the smRunTable is destroyed
when the value reaches 0 and the smRunState has the value
`terminated'.
The value of this object may be set in order to increase or
reduce the remaining time that the row may exist. Setting
the value to 0 will destroy this entry as soon as the
smRunState has the value `terminated'.