Date or time fields are broken out incorrectly.
Check the date or time field in the source database If you don't see the levels you expect in the date or time dimensions in your OLAP cube, check the date or time field from the underlying relational database that supplied the records for the query. The dates and times in the records might be stored as text instead of in a date or time format that the OLAP Cube Wizard can recognize. If you suspect this is the case, consult the database administrator for the relational database to verify and correct the date or time format for the field.
Check the top level of the dimension When the OLAP Cube Wizard adds date and time fields as lower levels of an existing dimension, the wizard does not automatically break the data out into year/quarter/month/week and hour/minute/second levels. The wizard does this only when you add the date or time field as the top level of a new dimension. If the date or time field is not the top level, modify the cube.