Final answer:
In views that don't have data import enabled, Custom Dimensions values cannot be viewed for dates before the Custom Dimension was created.
Step-by-step explanation:
In views that don't have data import enabled, Custom Dimensions values cannot be viewed for dates before the Custom Dimension was created. This is because Custom Dimensions store specific values for each hit, and if the Custom Dimension did not exist at the time of the hit, there is no data to display.