MsgBox-at the end a msgBox popup

I have a macro that run every 30 minute and at the end a msgBox popup show up
to say "I'll be back in Half hour BUT show up with a button "OK" and I
need press that button in order to run a macro again .

MY QUESTION IS THIS : Is it possible a msgbox popup and disappear , let
say 5 seconds later without human intervention ???

Thank in advance
Cc