Delaying a project planning

I am actually working on a project A which is planned for 15 days (01/04/2012 till 15/04/2012) and all activities have been recorded on the application. After 5 days (05/04/2012), I have another activity (duration = 1 day) from a project B which has higher priority than project A and need to be input on the 6th day (06/05/2012) of project A’s planning.

This delayed the planning of project A by 1 day and will normally finished on the 16th day (16/04/2012), which means that all tasks from project A as from the 6th day (06/04/2012) should be delayed by 1 day.

Is there a way to move all projects from the 6th day (06/04/2012) by 1 day? (i.e. move all activities on the 06/04/2012 for project A to 07/04/2012, and so on)
Or this should be done manually on all activities?