Has-arrived-delay

Has arrived delay (Boolean operator)
        Becomes true <delay> seconds after the specified ship(s) have arrived into the mission

Returns a boolean value; Takes 2 or more arguments:
        1:      Time delay in seconds (see above).
        Rest:   Name of ship (or wing) we want to check has arrived.

Comments

Ships that are present at mission start (=their arrival cue is "true") do not count as arrived. Including a ship like that as an argument for this SEXP will always return "false."