Dice with Holes

A cube starts off with no marking for the numbers one to six. You decide to mark the faces in the usual order by drilling holes into or through the cube, it may then look something like the green one above.
So the faces will need to look like this,

You'll need to find out how the numbers on an ordinary dice are arranged and then your challenge is to find the smallest number of holes that need to be made.
(Remember that when you drill holes you will drill at right angles to the face - perpendicular - so no slopes!)