Date dimension 4-4-5 then along comes a week 6!!

[cognosjon]

Hi,

I'm hopefully after a bit of advise or point in the right direction.
I've adopted some cubes which have been running for some time and the date dimension was set up using the date wizard following the 445 rule. I've today been advised that a week 6 has now been decided upon for year end. This as you will have guessed won't fit and will simply move into the new year.

Any suggestions/pointers as to what I could do here aside from hide under a rock?
The calendar is supported by a date dimension that is driven by our data warehouse so the correct dates are reported within the source file just not then replicated by the formatting of the date wizard.

Thanks