Kimballs design Tip#51 - Time Dimension

This tip suggests that we can eliminate the minute dimension and have a full time stamp in the fact row.I need more clarification on how this could be implemented. For instance if I need a fact to be shown with 1/2 hour split down how could I do it without a minute dimension?Could someone help me?

Concerning your business needs ( analyzing fact data in ½ hour classification ) you will however need a TIME dimension table besides the normal DATE dimension.
Your TIME table can look like

Time Id
Start Time
End Time

The table will contain 48 rows (24X2)

Of course you will connect your Fact table with that TIME dimension table and then you can analyze fact data in ½ hour classification.