Hi William, you should build some date buckets in the load script.
Go to the load editor and do something like this:
Year(floor([Datefield])) as Year,
'Q' & ceil( Month(floor([Datefield])) / 3) as Quarter,
Month(floor([Datefield])) as Month,
Date(floor([Datefield])) as Date,
The floor function is used to strip out the time aspect so that the bucketing loses the granularity you are getting but don't want.
Then you can create a master item / drill down dimensio nfrom Year to Quarter to Month to Date
Of course you can use these expressions in the UI, but it will calculate faster in the UI if you pre-calculate in the script first. Hope it help!