My current CRM installation involves the migration of customer data from the business system that runs the company to CRM.  While I am working through issues related to the migration process, I discovered that it would be very handy if I could see both the date and time for the created on Attribute displayed in the Active Accounts view.  Here's how I did it:

1) Select Settings, Customization, Customize Entities.

2) Customize the Accounts Entity.

3) Click on Attributes

4) Edit the createdon attribute.  You should see something like this:

5) Change the Format to Date and Time, as shown below:

6) Add the createdon attribute to the Active Accounts view, if it doesn't already exist.

7) Save and Publish your changes.

8) The Created On Attribute should now be formatted with both the Date and Time.

Caveats

The only issue I ran into was the fact that the Advanced Find still only recognizes the Date format of the createdon attribute.  If anyone knows a way around that, let me know and I'll update this article accordingly.