The calculation is correct, however, you need to have bucket on the view in order for the values to appear. Place it on the rows shelf and you'll notice that it works as expected.
Hope this helps!
Appreciate the feedback! I realize adding the bucket field to the view will allow the value to show up but I am looking to get the calculation without having to "group by" bucket. Essentially, I want each calculated field to be on the same line, which can't happen if I have the bucket in the view. Does that make sense?
This works when using dates, but doesn't work with text.