Yes, but you need to handle this as 2 separate actions to do that. One to make them an admin and logoff, and another to remove admin and logoff. The action to remove admin and logoff could be triggered after 4 hours or through a self-service offer whenever the user is ready to do so.
In general it is a bad idea to have a 4 hour wait timer in the middle of an action because this means BigFix will be stuck doing nothing for 4 hours.
See this related response: Can action continue after shutdown