Numberformat macro partially works, color changes, dateformat not

My macro does set a format but doesn't apply it.
When ik select the cell after running the macro and click in it, or press F2, than the format is applied.

I have a range of dates like f.i. 24-4-2015 and want to change it to 24-apr. I made the following macro

Please Login or Register  to view this content.

The dates turn red immediatly, but for applying the date format i need to click each cell.

What am i missing?
Any help is appreciated