Time dimensions are distinct from other dimensions because SSAS contains inherent functionality to group the members into levels. SSAS has built-in logic that puts the correct days into the correct months and the correct months into the correct quarter.
You can either use a Server Time dimension, or use a dimension table that contains time data. Server time dimensions contain hierarchies, levels, and attributes, but these are stored on the server rather than in a separate dimension table.
By default, a role that has access to a cube has read access to all of the dimensions in the cube. But access can be denied to one or more members in the dimension.
The default access is read-only, so users cannot process the cube. However, if you change the permissions of a relevant role to read/write, it will enable users to process the cube.
By default, permissions apply to all dimension members, but an MDX statement can be written to define a subset of the dimension.
An MDX statement can be used: