SSAS modify server time dimension

I have a cube wich has the tipical server time dimes开发者_如何学Cion (it's stored in the OLAP server, not on normal SQL server)... It has some members like month, year, 10 days,... but I want to add a new one (15 days). Is there an easy way to do it or should I create the dimension on the datasource?

Thanks.

---

You should create the dimension in the data source and then you can edit it as you like.